This PDF file contains the front matter associated with SPIE Proceedings Volume 11761, including the Title Page, Copyright information and Table of Contents

Refractometric sensors based on plasmonic resonances can be modified to operate using an interrogation method based on the optoelectronic response of the device. In this contribution we show how the bolometric effect can be used to generate a signal depending on the change of the refractive index of the analyte. The design has been tuned to sense variations in the range of aqueous media. We have also proposed a modification of a perovskite solar cell to sense variations in the index of refraction of air. These changes in the interrogation method have required a modification of the definitions of the sensitivity and Figure of Merit of such types of sensors. The results show a performance that is competitive with other refractometric sensors and allows an operation method that relies on the measurement of electric, or electronic, parameters.

Various ground-based and space-based future telescope technologies are currently being conceptualized, designed, prototyped and tested to perform next generation astronomical sciences. They include (1) the alignment of segmented multi-order diffractive elements for the Nautilus space observatory; (2) the inflatable terahertz OASIS space telescope primary mirror characterization metrology; (3) active alignment of the laser truss-based Large Binocular Telescope prime focus camera; (4) the modular cross-dispersion spectroscopy unit, MOBIUS, used at the prime focal plane of the Large Binocular Telescope; (5) pupil segmentation topological optimization for future high contrast imaging telescopes; and (6) the optical design of the long slit UV spectroscopy space telescope Hyperion. This suite of enabling optical technologies and concept designs will redefine how humans understand the genesis and future of our universe.

Dynamically tuning Q factor in optical resonators is now more feasible in information processing applications, such as light storage and wavelength conversion. This paper proposed and demonstrated a new dynamically tuning Q approach that is realized in coupled two rings structure. One resonator uses an add-drop configuration, coupled to another single micro-ring. The heating causes an increase in the refractive index, which in turn causes resonant wavelength redshift. This shift is a switch to control the coupling between the two rings, to tune the linewidth of light confined in the ring, equivalent to tune the quality factor. And we adjust the detuning and coupling state between the two rings to control the light coupled into the resonator. The Q factor decreases from 56,525 to 16,450 in the transmission spectrum with the different heater power. In this way, we successfully realized a modulation of the Q from high to low states in the structure. Besides, the original coupling spacing between the two rings also has an influence on the Q factor. The larger the coupling spacing, the higher the Q factor. In addition, we also study the changes of phase and delay time in the tunable process. The results show that the change of fast light (high Q) and slow light (low Q) can be realized at the same time, which would enable applications for on-chip adjustable time delay, fast/slow light and light storage.

To discuss the preparation technology of ultra-thin Polyimide (PI)/ Zirconium (Zr) self-standing composite film. Polyamide acid (PAA) solution was synthesized with 4,4'- diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA) as monomers. PI films were obtained by gradient temperature rise thermal imidization. A PI self-supporting film with a thickness of about 600 nm was obtained by the corrosion of ZnO release agent with dilute hydrochloric acid. After it was fixed in a copper frame with a diameter of 15 mm, a Zr film with a thickness of about 200 nm was deposited on it by direct-current magnetron sputtering. The composite film with a thickness of about 600 nm PI/200 nm Zr was obtained. PI film increased the mechanical properties of self-supporting Zr filter film, but in order to reduce the influence of PI film on the transmittance of Zr filter film, PI film was etched and thinned by excimer laser, and the thickness of 200 nm PI/ 200 nm Zr self-supporting filter film was prepared. This method deposited 200 nm Zr film on 600 nm self-supporting PI film, and then etched part of the PI film. 160 pulses were etched with excimer laser energy density of 40 mJ/cm² and 26 pulses were etched with 70 mJ / cm², and 200 nm PI /200 nm Zr self-supporting composite filter film was acquired respectively.

Fringe projection profilometry (FPP) has been more widely applied in fields such as intelligent manufacturing and medical plastic surgery. Recovering the three-dimensional (3D) surface of an object from a single frame image has always been the pursued goal in FPP. The color fringe projection method is one of the most potential technologies to realize single-shot 3D imaging because of the multi-channel multiplexing. Inspired by the recent success of deep learning technologies for phase analysis, we propose a novel single-shot 3D shape measurement approach named color deep learning profilometry (CDLP). Through `learning' on extensive data sets, the properly trained neural network can gradually `predict' the crosstalk-free high-quality absolute phase corresponding to the depth information of the object directly from a color fringe image. Experimental results demonstrate that our method can obtain accurate phase information acquisition and robust phase unwrapping without any complex pre/post-processing.

This paper presents a stellar point source background radiation model based on IRAS catalog, which is used to simulate the stellar background radiation signals of observers at any time of observation and in the field of view at any longitude, latitude and altitude. First, the data of stellar equatorial longitude, equatorial latitude, magnitude, and radiation intensity recorded at the epoch time in IRAS catalog is used to correct the proper motion, precession and nutation, and the coordinate information of the star at the specified time in the coordinate system of equatorial celestial sphere will be obtained. Then, after a series of coordinate conversions, with the occlusion of the line of sight being taken into consideration, the coordinates of the star at the time of observation are converted into the apparent position relative to the observer in the specified scene. On this basis, the infrared irradiance of stars in the specified field of view is calculated based on the radiation intensity data recorded in the star table. The research results have some reference value for the detection and recognition of space objects.

The surface plasmon has the advantages of breaking through optical diffraction limitation and local field enhancement. With the development of micro nanometer cycle structure of film/semiconductor rapidly, the cycle unit size tends to be nanometer level, therefore the requirement for purity and clarity is higher and higher. The existence of defect influence the quality of surface plasmon obviously , so it should not be ignored on the overall performance of optical system. In order to detect effectively the deficiency of surface plasmon, a surface plasmon structure model based on the plane type surface of periodic square hole which contains defective particles is proposed by Multi- Resolution Time-Domain (MRTD) method. The changes of the light scattering field when different defects appear in the structure of periodic square hole vitro exciter are focused on micro-and nanoscale, and we can analyze the influence of different structural parameters and defect parameters on the total scattering field to achieve effective control of the defects and modulation of the light field.

Usually, the practical analysis states of an imaging polarimeter needs to be calibrated, with a set of standard polarization states, for the accurate reconstruction of Stokes parameters. However, it is really challenged to get the standard elements over wide field of view (FOV), broad waveband, large aperture, or other non-trivial conditions. Even if the system is well calibrated, the calibrated system will be disturbed in the vibration environment. To avoid the difficult from the standard polarization states, an iterative reconstruction method is presented at the first time to recover the polarization parameters from the data acquired by linear-Stokes polarimeters without polarimetric calibrations. Inspired from phase shifting interferometry, the method employs two least-squares iterative procedure and requires no any extra element for assistant. And we extend the method to a channeled linear imaging spectropolarimeter, channeled linear imaging spectropolarimeter can measure a two-dimensional distribution of spectrally-resolved linear Stokes parameters in a single-shot polarization modulation. However, the state-of-art reconstruction method, Fourier transform method (FTM), usually transforms the modulated spectrum into the frequency domain for further processing. As a result, there is channel crosstalk issue that limits available frequency bandwidth. In addition, FTM needs extra phase calibration to decode final spectra. We present a continuous slide iterative method (CSIM) in the spectral domain to avoid the use of the Fourier transform and phase calibration. It combines a sliding unit cell kernel in the spectral domain that provides unit cell tracking and a loop of twostep least-squares fit that estimates spatially-resolved polarized spectra.

A solar-blind lidar system is developed by using Nd:YAG laser to produce 266nm wavelength at the frequency of 10Hz as the light source to to detect the height of boundary layer in Xi'an area. The observation experiment and analysis are made.The solar background light has no 266nm wavelength and the influence of it can be ignored in the daytime, and then all day detection can be realized. It can be detected in the daytime and nighttime. The wavelength of 266nm absorbed by ozone is considered only. The absolute minimum of first derivative and second derivative of the range-squared-corrected lidar signal are employed to retrieve height of boundary layer. Based on the observation of atmosphere in daytime and nighttime, the heights of atmospheric boundary layer are 0.44km and 0.47km, and the influences of meteorological factors and human activities on the height of atmospheric boundary layer are analyzed. The results showed that the lidar can satisfied the need for detection of troposphere atmospheric aerosol particles at all time and are beneficial to offer practical and effective data for monitoring atmospheric environment in Xi'an aera.

With the development of optical components towards low surface damage and low scattering characteristics, more and more attention has been paid to the surface integrity of optical components. Grinding is a common rough machining process for precision optical components, and its surface quality affects the subsequent polishing efficiency and the surface integrity of optical components directly. Therefore, in this paper, studies the grinding surface morphology of ZF62 optical glass material from many aspects such as grinding wheel modeling, surface formation mechanism, and abrasive movement analysis. The paper models the grinding wheel based on the power spectral density (PSD) of the grinding wheel surface, and verifies the effectiveness of the modeling method through experiments. Basing on analyzing the surface roughness with different grinding parameters, there are conclusions as follow: The modeling of the grinding wheel surface based on PSD could effectively simulate and analyze the grinding surface of the grinding wheel. Both the simulation experiment and the actual experiment show that the consistency of the trend. The surface roughness decrease with the increasing of the grinding speed and increase with the increasing of feed rate and the grinding depth.

Double random amplitude-phase encoding (DRAPE) system is immune to the conventional phase retrieval attack. Here, we demonstrate that the DRAPE system is vulnerable to the ptychographic phase retrieval method. By using the ptychographic attack algorithm, the keys of DRAPE system can be cracked. Moreover, since the question of the optical cryptanalysis can be transformed into a problem of ptychography imaging system, the ptychographic attack may further promoted to other the optical image cryptosystems.

The THz absorption spectrum of barbituric acid has been investigated utilizing terahertz time-domain spectroscopy (THz-TDS). The vibrational spectra of barbituric acid and its dihydrate have been studied in the framework of density functional theory using Perdew-Burke-Ernzerhof functional. In addition, the comparison of THz patters between barbituric acid and its anhydrate were also performed. It is found that four distinct THz spectral peaks and two shoulder peaks are exhibited in barbituric acid measurement. Peak assignment implies that all measured features come from the intermolecular forces. For barbituric acid dihydrate, three absorption peaks are predicted, which comes from the interactions of barbituric acid and barbituric acid molecules, barbituric acid and water molecules in solid-state. Finally, these different spectral patters indicate the ability of THz spectra to identify hydrate from anhydrate in practice.

The laser gyro mirrors were detected by laser scatterometer. It showed that the laser scattering of the mirror was large when there were different degrees of scatter bright stripes on the surface of the mirror. In this paper, based on the subsurface damage model of polishing, the whole process from polishing, cleaning and coating was studied, and the deep mechanism of the laser scatter bright striper was revealed. By improving the process technology, mirrors with small scatter spot and no scatter bright stripe were prepared.

An experimental investigation for the polarization analysis of the high power GaSb-based semiconductor laser diodes emitting at 2.1μm in terms of measuring Stokes parameters has been exploited and adopted, which gives further insight into understanding, manipulating and applying the polarization properties of the laser diode. Results of output performance and polarization behavior of the laser are presented in the paper. The average linear polarization of the laser diode reaches 97.72% with output power exceeding 1W at 3.5A under CW operation at 20℃, which demonstrates the dominant position of linear polarization light of the output beam. Highly linear-polarized properties could not only enhance the performance of high power GaSb-based laser diodes in traditional applications in laser processing and beam combing, but also open new application fields such as parametric convention and coherent detection.

Mid-infrared spectral region (2-4 μm) is acquiring significant attention due to the presence of various enabling applications in the field of remote gas detection, environmental pollution detection applications. Tm:YAP is an important crystal materials for diode-pumped laser emission of 2μm wavelength. We report a room-temperature diode pumped Tm:YAP thin disk laser. The maximum output power was 3.5 W at wavelength of 1940 nm.

Large ring laser gyros are regarded as suitable sensors for precise monitoring of the Earth’s rotation. Their long-term stability, high sensitivity, and mechanical properties suggest themselves for potential terrestrial deployment, such as Universal Time (UT1), Length of Days (LOD), Geophysics, etc. This inertial technology based on Sagnac interferometers measure any non-reciprocal effect which gives rise to a difference of optical path lengths between forward-propagating laser beams and the counter-propagating within the cavity. Differing from their cousins used in navigation, large ring lasers is usually a heterolithic optical cavity composed of four independent reflector components s to avoid employing large whole Zerodur. Comparing with other UT1 measuring technologies, large ring lasers has characteristics of higher resolution and good real-time, which is highly complementary to VLBI observation technology. In order to meet the measurement of UT1 error less than 1ms/day to coordinate with VLBI, the resolution of ultra-stable laser gyros must be better than 10e-13rad/s. The geometric stability of heterolithic ring cavity is demanded stringently. We simulated the intrinsic relationship between geometric deformation and scale factor of optical cavity. The influence of temperature on geometric deformation has been analyzed and the temperature compensation strategy is proposed. The temperature field distribution of the laser gyro is approximately evaluated by measuring the temperature network of some specific points.

This article studies two main ways of gamut expansion: improving the color purity of the primary color and increasing the number of primary colors. A program for the gamut coverage of the multi- primary color display system is written. The color coordinates of the laser TV developed by ourselves are measured and the actual value of color gamut is calculated. The test data verifies the simulation result.

With the improvement of processing level, the combination of laser technology and numerical control system has become the trend of laser precision processing system. Different materials also have different requirements on laser power. The system adopts the mode of PC+GTS motion controller to accomplish laser precision processing of different workpieces. The power of laser processing is changed by modifying the parameters of PWM signal with the instructions of human-computer interface program. The laser power can be adjusted quickly to achieve precision processing of different materials and types.

The combination of an absorption sheet, a high count rate detector and a low-power micro-focus source is used to simultaneously measure the transmission of the polycapillary focusing optical lens in a large energy range. This method places the micro-focus source, the absorber and the detector in a line, has highly operability in actual measurement. The X-rays below 8 keV were completely absorbed when adding the aluminum absorption sheet, and the transmission efficiency of the lens to X-rays below 8 keV was not measured. After the absorption sheet is added, the attenuation of the X-ray is not simply an exponential decay, but also the Compton scattering effect was involved.

There are different kinds of mirror in the space instrument. Sometimes, engineers use filling glue to fill the small gap of the lens and its frame. Thus the structure may be more stable. However, this kind of method could also bring some new problems. Because of different thermal expansion coefficient of the lens and frame, the thermal deformation may be different during the temperature change, which will affect the surface accuracy of the lens and the vibration response. The thickness of glue block and the distributed form of the glue are the key factors. The paper focused on these factors and did some simulations to find out how these factors affect the surface accuracy and fundamental frequency. Then, the paper gave some proposals on this issue.

Non-line-of-sight (NLOS) imaging technology is to ‘see’ the target out of sight, such as an object around a corner or hidden by some shelters. However, due to constraints of device definition and computing load, NLOS system is usually expensive and requires hidden objects with special material and simple shape. Besides, imaging space of system is limited. We perform a series of simulation with 1550nm infrared laser to expand the application field and improve the performance of NLOS system. Based on math and physical properties, main experimental components are modeled and data acquisition process is completed first. Then, the ellipsoid inversion algorithm is used to reconstruct the hidden space and imaging results are obtained. Finally, multiple series of system parameters are set and their influence on imaging results is analyzed. Results demonstrate that echo signal intensity after multiple reflections provides adequate information to reconstruct the geometry of a hidden object. However, the number of laser scanning position, resolution of detector, voxel division and location of the scanning area will all have a critical influence on NLOS imaging results.

Full aperture polishing (FAP) is widely used as the final finishing process of large optical flats to obtain super smooth surface. The polishing pad is an important part in the FAP system, and its conditioning accuracy has a great influence on the polishing flatness of the component. However, the traditional full-aperture conditioning method (FCM) has been unable to meet the current use requirements, especially for large-size polishing plate. In this paper, we propose a subaperture fixed connection conditioning method (SFCCM), which reduces the size of conditioner and adds its movement. Based on the theory of multi-system kinematics and coordinate transformation, the formation mechanism of the surface profile error of pad is studied, the conditioning error transfer model is established, and the main error factors that affect the conditioning accuracy are pointed out. Through error compensation, the conditioning accuracy is improved. Experimental results showed that SFCCM has a better surface profile modification effect than FCM. Furthermore, the surface accuracy of the optical component of SFCCM is higher than that of FCM in the same FAP process.

Mechanical structure, of which a trade-off between weight and strength has always been considered primely, is important for a space camera as a hub for other assemblies such as optics parts, electronic parts, etc. Traditionally the space camera is composed of a nearly line-up of arrangements containing different units, which is easy to assemble and manufacture, however, not a good type for mechanical properties due to the cantilever structure. We present a new type of unitized design for the structure of the space camera, which unite the tube and the electric cabinet as one unit, with the PCBs (Printed Circuit Boards) surrounded. The main frame is optimized by using topology optimization, improving the characteristic of the structure. The maneuverability has also been considered. Compared with some traditional type, the new type proved to be lighter and more compact, which is beneficial to the mechanical properties and the cost control of satellite launching.

Epidermal layer recognition is an effective way to diagnose the severity of psoriasis and other skin diseases. Optical coherence tomography (OCT) is a non-invasive imaging modality that acquires images of tissue in vivo and plays an important role in detecting skin diseases and assessing therapeutic effects. In this paper, a method for epidermal layer recognition of OCT skin images is proposed. Firstly, the skin surface is obtained based on the axial gradient map. Then the original image is flattened according to the estimated skin surface. And the potential region of the dermo-epidermal junction (DEJ) is obtained according to the mean column signal. Finally, the epidermal layer is identified by topology transmission and seed filling. The method can automatically segment the curved mastoid structure of the DEJ which is suitable for OCT images of skin with weakened signal intensity of dermis due to dermatitis or other diseases.

A graphene-coated terahertz photonic crystal fiber (G-PCF) for refractive index (RI) sensing is proposed and numerically simulated by the finite element method (FEM). To enhance the sensitivity and produce birefringence, two larger air-holes are introduced in the innermost ring of holes around the solid core. Inner surface of the larger air-holes is coated with multilayer graphene and used for analyte filling. The guided modes of the designed G-PCF are distributed mainly in the larger air-holes as a result of the high permittivity and carrier mobility of graphene. The relative sensitivity coefficient can be improved more than 5 times by introducing the graphene coating for analytes with a RI in the range of 1.00 to 1.50. The highest relative sensitivity coefficient about 90% is obtained when RI is equal to 1.37. The relative sensitivity coefficient can be improved more than 15 times with RI equals to 1.03. The propagation properties and RI sensitivities of the G-PCF can be electrically and thermally controlled. Our results provide references for RI sensor applications of the designed GPCF in terahertz range.

For large aperture and high-resolution space optical cameras, the focusing requirements caused by different resolution requirements, or the requirements for the segmented primary mirror for deployable telescopes or on-orbit assembly space telescopes, the micro- or nano-metric multi degree of freedom adjusting of the primary mirror or the segment mirror is one of the inevitable development trends of the active optical system. According to the different degrees of freedom involved in the primary mirror adjustment, the micro- or nano-metric multi degree of freedom adjusting displacement scaling mechanisms of the monolithic and segmented primary mirror are studied. The development history and structural characteristics of multi degree of freedom adjusting displacement scaling mechanisms including rigid lever type, gear deceleration type, hydraulic mechanism type and compliant hinge type, as well as their research status and application fields, are introduced. The performance characteristics and applications of various displacement scaling mechanisms are analyzed and compared. Finally, according to the application requirements of space telescopes in the future, the development trend of multi degree of freedom (DOF) adjusting displacement scaling mechanism for segmented primary mirror is proposed.

An optimized depth-resolved dispersion compensation method for achieving better dispersion compensation effect is presented in optical coherence tomography signal processing. When performing depth-resolved dispersion compensation, it is necessary to use a rectangular window function to intercept the interference signals at different depths of the sample from the A-line signal before FFT. Windowed FFT will cause errors in phase extraction, which will lead to inaccurate dispersion coefficient. Herein, the rectangular window function needs to be optimized. The phase is extracted after FFT of the interference signal obtained by the primary rectangular window. According to the functional relationship between the phase and the wave number in the presence of dispersion, the obtained phase is fitted to the quadratic polynomial by the least square method, and the standard error of the fitted quadratic polynomial is used as the criterion. Constantly changed the width and center position of the rectangular window to obtain the smallest standard error. The smallest standard error corresponds to the optimized rectangular window, which is used to intercept the signal and perform FFT to obtain a phase close to the true value. Therefore, the dispersion compensation coefficients of the OCT system at different depths are accurately extracted. It is verified by simulation and experiment that this method can achieve better dispersion compensation effect.

With the development of the modern state of optical engineering, large diameter (400×400 mm) of optical element processing and its whole surface shape accuracy is 0.1 micron (λ/ 6). It's on special crystal material single point diamond fly knife cutting ultra-precision machine tools put forward higher request, the bed is equipped with stable, the lathe bed equipment for the foundation design, and set the parts of the material. We think about the precision analysis of the external influencing factors of equipment, and design the model of equipment bed. In the bed model, the static simulation analysis is made under the two schemes of basic design and optimized reinforcement, respectively. And we compared the necessary design model and optimized design model. The total deformation was 0.409 microns for bed base, 0.268 microns for oblique rib, and 0.312 microns for circular rib. And we analyzed the deformation in X, Y and Z directions.

The ultrafast all-optical solid-state framing camera(UASFC) technique is a new diagnostic method based on the semiconductor photorefractive effect. The ultra-fast response characteristics of this method are mainly determined by the response time of the semiconductor material's photorefractive index change. How to quickly and accurately measure the photorefractive index response time of semiconductor materials is an important step in the development of all-optical solid ultra-fast diagnostic chip. In this paper, the 100fs pulsed laser is divided into two beams. One of which is used as excitation light to generate pulsed X-ray source; the other beam is measured as a spectral probe light. Through the test of GaAs material, the response time of the refractive index change of GaAs material was less than 5ps, which laid a foundation for further optimization experiment and accurate measurement.

In the lens-based imaging model, the Scheimpflug principle is expressed as the object plane, the image plane, and the lens plane intersect in a line. With this principle, the object surface in front of the lens can be tilted by installing a tilted sensor, thereby significantly extending the axial distribution of the clear-imaging area. In order to calibrate the bi-telecentric lens under the Scheimpflug condition, we derived a concise imaging model, and the corresponding calibration method without solving the rotation or tilt angle is proposed. The re-projection error is calculated in the experiment to verify the effectiveness of our method.

We present a spectrum aliasing minimization scheme for Fourier ptychographic microscopy (FPM) based on annular illumination pattern optimization. Normally, the Nyquist sampling criterion under the coherent illumination case is required due to the quasi-coherent illumination system used in the conventional FPM technique. However, the spatial sampling criterion changes with the oblique illumination angles. When the illumination NA matches the objective NA, the spatial sampling criterion should be reconsidered under the incoherent case, since the phase information is lost during intensity imaging. In this paper, an optimal annular illumination based Fourier ptychographic microscopy (OAIFPM) method is proposed. After investigating the spectrum aliasing characteristic of different spatial sampling rates and establishing an objective cost function related to the spectrum aliasing percentage and reconstruction error, the reconstruction accuracy can be improved while the incoherent spatial sampling criterion is not satisfied. The results suggest that our OAIFPM system could be a powerful imaging technique for various high-throughput microscopic applications, such as drug discovery, cellular phenotypes characterization, and identification of disease mechanisms.

This article uses AT89S51 single-chip microcomputer as the CPU of the human body temperature measurement system, uses the MLX90614 sensor to measure the body temperature, assists the use of the HC-SR04 ultrasonic module and the DS18B20 digital temperature sensor to measure the distance between the target and the system and the ambient temperature, and displays the temperature on the LCD system . It is suitable for non-contact measurement in public places, and can detect body temperature quickly and effectively with high accuracy.

In order to further study the performance of laser illumination systems, a Monte Carlo simulation system is established for the return photons when laser illuminating the target. The physical process of photons from the emission to reception is simulated. The laser illumination system involves vacuum laser transmitting, atmospheric turbulence and return photons processing. Based on the simulation system, the quality of the laser far field spot is verified and the character of return photons is analyzed. The simulation results demonstrate that the simulation system performs well and satisfy requirements for research of laser illumination system with atmospheric turbulence.

For passive polarization detection, limited by the scattering medium and the sensitivity of the detector, the detector usually can only receive the polarization information of the weak target. Moreover, nonlinear operators usually amplify the influence of noise in polarization parameter images. These factors result in low SNR of polarization images, which affects the application of polarization technology in different fields. This paper proposes a polarization image layering algorithm based on the principle of biological vision, which uses the statistical characteristics of the angle of polarization (AoP) as the weight parameter to perform contrast enhancement and denoising operations on the degree of polarization (DoP) image. And the final result can be obtained by simple fusion. Experimental results demonstrate that the algorithm is capable of improving the DOP of the target while suppressing background noise, which may provide new ideas for the application of polarized target detection and polarization visualization in interdisciplinary fields.

According to the phase gradient transfer function (PGTF) derived from the phase space theory, the phase recovery algorithm based on the transport of intensity equation (TIE) has the problem that the high-frequency phase is underestimated due to the coherence effect of the limited aperture system under partially coherent illumination. Therefore, based on the theory of PGTF and phase transfer function (PTF), a phase reconstruction algorithm named high-resolution synthetic spectrum (HSS) method combining the TIE and the PTF-based deconvolution is proposed. This technique broadens the application range and provides high contrast, high accuracy, and highresolution quantitative phase results with high robustness. The performances of this technology are demonstrated by simulation and experiments, showing efficient for phase retrieval in the near-Fresnel region. Such a highresolution method can offer a flexible and cost-effective alternative for biomedical research and cell analysis, providing new avenues to design powerful computational imaging systems

In recent years, the development of computational imaging technology provides a new method for the realization of non-scanning super-resolution imaging. In this paper, a pixel super-resolution algorithm based on Fourier ptychographic technology is proposed, and the corresponding integrated and systematic programmable aperture coded super-resolution imaging system is constructed. By modulating the intensity with the coded aperture mask, utilizing different system point spread functions to obtain multiple samples of the original scene, and finally adopting sparse optimization iterative algorithm to reconstruct the original image, the result of super- resolution imaging is more than 3.5 times of Nyquist sampling frequency. In this tutorial, the proposed new super-resolution photoelectric imaging technology innovatively adopts the approach of coded aperture to realize image super-resolution imaging and effectively solve image pixelation. High-resolution images beyond the spatial resolution of the detector are obtained without any physical moving device or scanning mechanism. Compared with the traditional micro-scanning technology, it not only improves the reliability and stability of the system but also greatly reduces the cost and volume weight of the system.

To improve the recognition ability of optical imaging system for UAV (unmanned aerial vehicle) target, a synthetic aperture optical imaging system is proposed and designed. Firstly, according to the target size and detection distance the desired parameter indexes of the optical system are confirmed; Secondly, the suitable systematic structure is selected and the initial structure parameters are analyzed; finally, through the optimization of the Zemax software, the spatial resolution of the system at visible wavelength can reach 0.5mrad/pixel, and the detection distance of typical UAV targets in the air achieves 2km. Comparing with the high processing cost of single large optical components in traditional optical system, the design method of the synthetic aperture optical system is feasible, and the processing cost of small aperture optical components can be saved effectively.

The use of wind imaging interferometer to retrieve wind field information requires high accuracy of the instrument in phase shift. Traditional wind field inversion algorithms invert wind field information such as wind speed and temperature based on equal phase-shift interferometers. In actual situations, the phase shift of the wind imaging interferometer does not perfectly meet the design requirements, producing inversion result errors. In this paper, the inversion algorithm of an arbitrary phase shift wind imaging interferometer is studied, and the feasibility of the AIA (advanced iterative algorithm) inversion algorithm is verified under the condition of low accuracy of the instrument phase shift. The comparison of the inversion results of the AIA algorithm in wide-field interference and non-widefield interference are respectively discussed. The influence of the unevenness of the strip system caused by the temperature distribution on the inversion accuracy of the AIA algorithm is analyzed. The conclusions of this paper can provide theoretical support for phase-shifting calibration of wind imaging interferometers and wind field information inversion in low-precision instrument.

In recent years, the convolution neural network has been widely used in single image super-resolution and has an excellent super-resolution ability. In this paper, a novel convolutional neural network structure based on symmetric skip connection is proposed, which contains multiple convolution layers and deconvolution layers. The role of the convolution layer is to extract the details of image content, and the function of the deconvolution layer is to make the image upsampling and restore the image content details. In addition, we use skip connection between the convolution layer and the deconvolution layer of network structure, which can transfer image information from the front end to the back end. Meanwhile, skip connection can also effectively solve the problem of gradient vanishing. Besides, the residual block is introduced to deepen the network structure. The deeper network structure can learn more complex changes. Different from other papers, this paper uses the method of adding the number of channels for feature fusion. This method can greatly increase the number of feature images, which is helpful to restore image details by deconvolution layer. A large number of experiments show that our network has efficient super-resolution ability of infrared image details.

In the recording process of phase-shifting profilometry, intensity fluctuation caused by uorescent light source instability may occur and then introduce a non-ignorable phase error. More importantly, the selection of sampling speed will also affect the value of the phase error, which even up to 0.12 rad. To suppress this problem, a deep learning-based fluorescent light error suppression (DLFLES) method is proposed to achieve high-precise measurement under fluorescent light. Experiments demonstrate that the shapes of the reconstructed 3-D images are more precise using the proposed method. Our research would promote the development of accurate 3-D measurement under the interference of external light sources by using deep learning.

Classification is the focus and difficulty of hyperspectral imaging technology. Hyperspectral data have twodimensional spatial information and one-dimensional spectral information, which are presented as three-dimensional data blocks with large amount of information, meanwhile high-dimension, high nonlinearity and limited training samples bring great challenges. Deep learning can extract and analyze the features of target data step by step by building multi-layer deep nonlinear structure. The advanced feature, multi scale abstract information extracted by convolution neural network applied to image processing can improve the classification accuracy of complex hyperspectral data. We regard pixel level hyperspectral classification as semantic segmentation network, and creatively introduce squeeze-and-excitation network and pyramid pooling network into hyperspectral classification network and proposed a model based on the structure of 2D-3D hybrid convolution neural network, it can learn deeper spatial spectral features and fusion to improve the accuracy and speed of hyperspectral classification.

To overcome the shortcomings of the existing rectangular electrode coplanar capacitive sensor used in the non-destructive detection, such as poor adaptability to the uneven distribution of medium, small dynamic range and low sensitivity, a two channel coplanar capacitive sensor with triangular electrode is proposed, and a method of applying it to non-destructive detection is discussed. Firstly, the sensor structure and mathematical model of the novel coplanar capacitive sensor is established, and the sensor related performance indexes are analyzed and defined. By establishing a three-dimensional simulation model of the sensor, the influence of sensor structure parameters such as working electrode, shielding electrode, protective electrode and substrate thickness on its performance indexes is systematically analyzed. Through studying the correspondence between different performance indexes and structural parameters, the linear relationship between the penetration depth of sensor and the electrode structure parameters is established. Finally, experiments are conducted to evaluate its performance on non-destructive detection.

Fringe projection profilometry (i.e., FPP) has been one of the most popular techniques in three-dimensional (i.e., 3-D) measurement. In FPP, it is necessary to obtain accurate desired phase by using a small number of fringes in dynamic measurement. Recently, fringe pattern transformation method (i.e., FPTM) is proposed based on deep learning, which can achieve accurate 3-D measurement using a single fringe, but the phase error is still higher than the phase-shifting algorithm. In this paper, the phase error of FPTM is analyzed and the relationship between it and local depth change rate is illustrated firstly. Then, the accuracy of FPTM can be improved by using more fringes. Compared with traditional methods, FPTM can achieve higher precision 3-D measurement when less fringes are used.

Recovering the object hidden in the disorganized speckle pattern generated through diffusive materials is an important topic as well as a difficult challenge. Existing speckle correlation imaging approaches generally use the speckle autocorrelation to extract the Fourier amplitude information of the target. Our goal here is to research the effects of the quality of the speckle autocorrelation on reconstructing targets via HIO-ER (hybrid input-output and the error reduction) algorithm. Specifically, a low-quality speckle pattern is preprocessed to estimate a high-quality autocorrelation. The PSNR of preprocessed autocorrelations could be increased from 5.88 dB to 24.08 dB. We also compare the differences between the preprocessed and unprocessed methods, and the reconstruction quality could be significantly improved than the later one. The result indicates that a high-quality speckle autocorrelation obtained after preprocessing helps to optimize reconstructing targets

This paper proposes a differential compensation system with a differential optical path which is consisted of a pentaprism, a half-pentaprism and a beam splitter. This system can split the source laser beam into two equal and opposite laser beams without considering the thickness of the beam splitter. Thus the average of the positions of the two laser beams remains constant despite the laser beam dithering angle. Simulations verify the feasibility of this system in ideal situation. Furthermore, the compensation error is analyzed taking into account the thickness of the beam splitter. Theoretical analysis shows that the system error is within 6 μm. Monte Carlo simulation are then verified that the collimated laser beam dithering can be reduced within 7 μm considering the machining error of the parameters of the prisms and the system error. This system with advantages of compact structure, free from electro magnetic interference(EMI) and transplantation, is wildly used in one dimensional measurement fields especially for the compact and containment detecting setup.

Eccentric fiber Bragg gratings (EFGBs) in standard single-mode optical fiber by using point-by-point direct writing technique with 800 nm femtosecond laser. The experimental results show that the transmission spectrum amplitude is coupled by Bragg and cladding mode resonance over a wide spectrum range. Meanwhile, the spectral characteristics of EFBGs were studied by adjusting grating period, grating length, laser power and eccentric distance. The eccentric distance is the most essential parameter in terms of inscribing gratings. It can break up the original structural symmetry of the fiber by changing the offset of grating in the fiber core. This change will bring great opportunities and breakthroughs to the application of EFGBs.

Phase space optics allows the four-dimensional simultaneous visualization of both space and spatial frequency optical information. The Wigner distribution function (WDF) is a common characterization of the phase space. Compared with the two-dimensional complex amplitude coherent optical field, the WDF can characterize optical field with arbitrary coherent states due to its higher dimensions. It is especially advantageous for the representation of partially coherent optical fields. The WDF is real and may have negative values, which are the result of phase-space interference. In this paper, an improved phase-space retrieval method is demonstrated. First, capture three-dimensional intensity focal stack. Then, phase space tomography (PST) combined with a non-linear iterative projection algorithm is conducted to reconstruct the whole WDF. We further analyzed the effect of the microscopy imaging system, i.e., the illumination aperture and the aperture of objective lens effect.

Phase unwrapping is an essential procedure in digital holographic microscopy (DHM). There are many algorithms have been proposed to unwrap the phase such as the reliability-guided phase unwrapping algorithm that intro- duced in this paper. It is necessary to do a comparison of these algorithms in order to determine which method has better performance in the actual experiment. For higher quality and fewer error points, we also introduce an improved phase unwrapping path base on path-following method such as the reliability-guided phase unwrapping algorithm, and the experimental images demonstrate the validity of our algorithms. In addition, we propose a method to accelerate the phase unwrapping process for biomedical dynamic imaging. The experimental results suggest that this method can significantly improve the dynamic measurement speed while ensuring the accuracy of phase unwrapping.

Polarizing beam splitter is designed with a broadband and wide range of incident angle. Polarizing beam splitter designed here is a kind of double periodic subwavelength medium-metal grating, which consisted of silicon dioxide as the substrate, magnesium fluoride (MgF2) as medium material and silver for the grid lines. It has the polarization splitting function of TE reflection and TM transmission. Based on the rigorous coupled-wave analysis(RCWA) and the continuous optimization of the structure parameters, the polarization beam splitter has high polarization conversion efficiency, high extinction ratio and a wide tolerance of incident angle in the near infrared band (1μm − 3μm) .The simulation results show that the reflection efficiency of TE polarized light and the transmission efficiency of TM polarized light are both higher than 96%, and the reflection extinction ratio and transmission extinction ratio are greater than 17dB and 28dB respectively. When the incident angle of incident light is from -80° to 80°, the reflection efficiency of TE polarized light is over 96%; when the incident angle is from -40°to 40°, the transmission efficiency of TM polarized light is over 90%. The reflection extinction ratio exceeds 17dB, and the transmission extinction ratio exceeds 35dB in the incident wavelength of 1550nm.The designed polarizing beam splitter is expected to be used in optical communication, optical storage, optical sensing and other fields for light modulation and control.

This paper proposes a flexible and stable method to generate cylindrical vector vortex beams with different topological charges using Single-polarization Vector Optical Generators (VOG). VOG is composed of two single-polarization responsive cylindrical lenses placed oppositely at a certain distance, which is a convenient implementation of the coherent superposition by means of two orthogonally circularly polarized states instead of path interference of interferometer. In this experiment, the customized computer generated holograms are loaded on the spatial light modulator(SLM) to generate Laguerre Gaussian (LG) beams with arbitrary topological charge, and LG beams convent to vector vortex beams with corresponding topological charge through VOG. The interference pattern of the two beams projected to a linear polarization state also give the cylindrically symmetric petal beams. And the diameters of vector vortex beams with different topological charges are also measured.

In order to improve the accuracy and efficiency of structural impact monitoring, this paper proposes a beam focusing impact localization method based on array sensor scanning. The circular array sensor arrangement method is adopted. Perform software-level impact damage monitoring on large-scale structures through different linear arrays forming a circular array, The effectiveness and practicability of the method are verified through the experimental research.

A high frequency fiber Bragg grating (FBG) accelerometer based on corrugated diaphragm has been proposed. The mechanical model is demonstrated. The accelerometer contains four parts, corrugated diaphragm, a FBG, two mass blocks, shell. The corrugated diaphragm is fixed on the shell. The upper and lower parts of the diaphragm center are symmetrically fixed by two mass blocks. The FBG is glued between the bottom of shell and mass blocks through a microhole. The amplitude-frequency and sensitivity of the accelerometer are theoretically analyzed and experimental measured. Experimental results show that the resonant frequency of the accelerometer is 490Hz, the sensor has a broad flat frequency range from 20 Hz to 350 Hz, the sensitivity of the accelerometer is about 50.3 pm/G with a linearity of 0.9997. The cross-sensitivity of the accelerometer is tested and the cross-axis sensitivity is about 8% of the main-axis. The accelerometer has a wide frequency and high sensitivity, which is promising in cross well micro-seismic exploration.

This paper introduces an auto-focusing reflection-type lens-less digital holography microscopic system, which has the characteristics of wide field of view, high precision and miniaturization. It can quickly and accurately carry out three-dimensional (3D) reconstruction and quantitative measurement of small devices with reflective surfaces. The system uses 632.8nm laser illumination. After coherent imaging, the hologram is collected by a board-level camera, and digital holography technology is used for phase recovery and 3D reconstruction. At the same time, the compact design of the system and the use of the board-level camera have reduced the overall size to only: 68mmx43mmx38mm. Its auto-focusing function has better focus accuracy and recovery quality than traditional manual adjustment. In addition, we experimented with a miniaturized chip which is micrometers in size, reconstructed its 3D shape, and gave the effect of auto-focusing experiment.

In order to solve the problems of no uniform coating, edge coating, and severe coating defects in the process when processing 430mm×430mm optical components, The basic requirements of surface roughness data acquisition are analyzed and the application of inductive sensor in surface roughness is introduced. Optical element flattening layer coating and flow direction mechanisms, flattening layer material selection, and research on material characteristics and optical element planarization layer deposition process, achieving uniform coating of optical elements, reducing coating defects, and meeting the requirements of the next process polishing

Based on the principle of acousto-optic tunable filter and aperture division, the new method that can obtain a high spectral full polarization and image information was proposed. It was improved the accuracy of target detection and object recognition by this method. The Optical system of polarization imaging spectrometer based on aperture divisionandacousto-optic tunable filter was designed in this paper, which was used in the 2.16-meter telescope and spectral range is 450-900 nm .First,the working principle of polarization imaging spectrometer based on aperture division was introduced.Then, the design scheme of optical system and the principle of information acquisition were studied.Finally, the design parameters were assigned and theoptical systems were designed.The whole system MTF reach 0.6 in 32lp/mm.The olarization imaging spectrometer based on aperture division can improve the observation capacity.

The finite element analysis method is mainly used to analyze the displacement and deformation of the lens under the action of gravity. The lens with a diameter of 320 mm and a thickness of 80 mm is used for simulation analysis. The simulation was carried out using the ring-belt support, the groove support, and the T-bracing, and the final deformation data was simulated and compared. The amount of deformation of the ring-shaped structural support was the deformation of the support of the groove structure, and the T-shaped support structure. Deformation. In addition, simulations were performed on various sizes of various support structures. It was found that the effect of changes in dimensions and structure on the final deformation was significant. By changing the diameter and thickness of the lens, the changing trend of the deformation of the lens under different thicknesses and diameters is obtained. The analytical method was used to calculate the deformation and compared with the numerical simulation method. The simulation structure was similar to the analytical results, and the accuracy of the simulation results was verified. In the end, we obtained the minimum deformation of the belt support, and simulate the three-dimensional deformation of the bottom surface. According to the requirements in the actual project, we designed the most appropriate clamping method for the interferometer.

Single image super-resolution (SISR) is a notoriously challenging ill-posed problem that aims to obtain a high-resolution output from one of its low-resolution versions. Recently, powerful deep learning algorithms have been applied to SISR and have achieved state-of-the-art performance. In this paper, a high-efficiency infrared image super-resolution algorithm based on a cascaded deep network is proposed. In this method, the low-resolution infrared image is directly processed without the preprocessing of bicubic interpolation up-sampling that can reduce the complexity of the network and the amount of computation. The network structure consists of two layers of the network. The sub-pixel convolution in each layer can enlarge the image size by twice and make the input image size to reach the final high-resolution image size. Besides, we utilize multi-scale feature extraction blocks to extract features from the same feature image by using multiple convolution kernels of different sizes, which makes the feature image information more abundant. The experimental results show that the test speed of each image in our network is 0.046 seconds, which manifests our proposed algorithm has high efficiency of infrared image super-resolution.

In the field of microscopic imaging, obtaining high-resolution images with a large field of view and depth of field has important research significance. However, as the numerical aperture increases, high lateral resolution cannot be balanced with large field of view and high longitudinal resolution. In order to solve this contradiction, this paper proposes a microscopic system design based on the cooperation of software and hardware. In the VS environment, the Qt development framework is used for system development, and the software is used to drive the movement of the platform and the camera to capture images then the image fusion is performed on the computer side. Aiming at the contradiction between resolution and field of view, this system adopts image registration and image fusion algorithm based on phase correlation method; for the conflict between resolution and depth of field, this system adopts image fusion algorithm based on minimum brightness; the auto focus function adapts variable step traversal method to locate the focus surface. The microscopy system equipped with the above functions can efficiently realize the acquisition of high-resolution images with large field of view and large depth of field, making computational microscopy imaging analysis more intelligent and automated.

Change detection (CD) is the process of identifying differences in the state of an object or phenomenon by observing it at different times. CD is one of the earliest and most important applications of remote sensing technology. The hyperspectral image (HSI) of remote sensing satellite provides an important and unique data source for CD, but its high dimension, noise and limited data set make the task of CD very challenging. Traditional algorithms are no longer suitable for hyperspectral data processing. Recently, the success of deep convolutional neural networks (CNN) has widely spread across the whole field of computer vision for their powerful representation abilities. Therefore, this paper combines traditional algorithms and deep learning techniques to solve the CD task of hyperspectral remote sensing images. The proposed two-branch Unet network with feature fusion (Unet-ff) model in this paper uses neural networks to automatically extract features to achieve end-to-end change information detection. In order to improve the degree of automation in the application, we select the most effective results as the training sample for the neural network which obtained by various traditional algorithms, and use ground truth to evaluate the detection results. For the characteristics of hyperspectral data, we use effective dimensionality reduction methods and rich data amplification methods to improve the detection accuracy. Experimental results show that our method can achieve better results on the existing classical datasets.

Full aperture rapid planar polishing (RPP) equipment has been widely used in the field of optical processing, which requires high precision and stability of the polishing shaft. With high stability and sustainability of precision, the aerostatic bearing is the potential technology for RPP machine. To meet the needs of RPP machine, Fluent was used to analyze the load-bearing characteristics of high-precision aerostatic bearing. Based on the simulated results, the parameter optimization design for porous aerostatic bearing was conducted to get better load-bearing characteristics, including bearing capacity, static stiffness and gas consumption. The influence of air supply pressure, porous material thickness and film thickness on bearing characteristics were studied, and the simulation analysis was performed to get the optimal design parameters for aerostatic bearing. The simulated results show that the designed high-precision aerostatic bearing can satisfy the requirements of RPP machine.

A DF chemical laser can transfer chemical energy into high-power laser beam in the megawatt range, which may be used for industrial manufacturing or military purposes. Reacting flowfield and optical field always interact in the process of optical energy extraction from the chemical laser cavity. On the one hand, nonuniform distribution of gain medium may affect the transmission of light beams, may lead to light deflection and phase deviation furtherly. On the other, power extraction may cause the variation of species and energy distribution in the flowfield. Therefore a numerical simulation is presented for investigating the interaction of chemical reaction flowfield and optical field. An 11-species (including DF molecules in various excited states of energies), 23-step chemistry model is adopted for the chemical reaction of the DF chemical laser system. Meanwhile, laser oscillating in the optical cavity is solved by geometric optical models. Variations of flow and optical fields from the establishment to the stabilization status in the optical cavity are simulated. Major results reveal that stimulated radiation has dominant effects only on the concentrations of the lasing species (DF excited molecules), and it has relatively minor influence on the basic fluid dynamic variables. For the case without lasing, the complete population inversion phenomena could be found in wider range, which does not occur for lasing. The lasing output is based on the partial population inversion of the vibration-rotation transition in DF molecules.

In this paper, using Preston hypothesis and CCOS removal model, analyzing removal function of the spherical polishing end is analyzed as Gaussian distribution, four schemes are proposed to design the robot optical spherical polishing end effector. Through the analysis and comparison of advantages and disadvantages, an optimal solution is obtained and a standardized design is carried out to realize the synthesis of revolution and rotation of the spherical polishing wheel. The design of the spherical polishing tool adopts bevel gear transmission, belt transmission and planetary gear structure. When the motor input is 200r/min, by adjusting the specifications of the pulley, the spherical polishing wheel can achieve a revolution speed of 60r/min and a rotation speed of 100~400r/min. After the design is completed, finite element analysis is performed on the important parts of the structure, and the designed structure meets the strength requirements.

Partial coherent imaging, which provides high robustness and twice the imaging resolution of the coherent diffraction limit, has become a hot research method in quantitative phase imaging. Asymmetric illumination is one of the most common methods to generate phase contrast for weakly absorbed samples. By establishing a strict intensity-phase model, the quantitative phase distribution of the sample is then obtained by inverse algorithm. In order to linearize the imaging process, weak phase approximation, which imposes restrictions of small value phase on sample, is introduced into the partially coherent imaging model to separate the sample absorption and phase. However, the weak phase approximation introduces an uncertain phase loss in quantitative phase imaging, especially for samples with a large phase. In this paper, we investigate the quantitative definition weak phase approximation for partial coherent quantitative phase imaging under asymmetric illumination by simulations. According to the simulation results, we find that the reconstruction accuracy of the weak phase approximation is not only determined by the absolute phase value of the sample, but also a effected by the illumination aperture. Furthermore, a quantitative definition of the weak phase approximation is given to provide a basis for the phase reconstruction accuracy for quantitative phase imaging based on asymmetric illumination.

Using a single fringe image to complete the dynamic absolute 3D reconstruction has become a tremendous challenge and an eternal pursuit for researchers. In fringe projection profilometry (FPP), although many methods can achieve high-precision 3D reconstruction from simple system architecture via appropriate encoding ways, they usually cannot retrieve the absolute 3D information of objects with complex surfaces through only a single fringe pattern. In this work, we develop a single-frame composite fringe encoding approach and use a deep convolutional neural network to retrieve the absolute phase of the object from this composite pattern end to- end. The proposed method can directly obtain spectrum-aliasing-free phase information and robust phase unwrapping from single-frame compound input through extensive data learning. Experiments have demonstrated that the proposed deep-learning-based approach can achieve absolute phase retrieval using a single image.

Blood glucose monitoring is very important for individuals with diabetes due to its rate determining role in medication strength adjustment and observation of possible life-threatening hypoglycemia. Of the many sensor modalities tried, the combination of electrical and optical measurement is among the most promising for continuous measurements. The traditional single optical method of acquiring data was simple. The complexity of blood components, and the influence of external factors, affected accuracy of the blood glucose. We proposed an accurate computational intelligent approach using support vector regression models to estimate blood glucose concentrations of serum samples by a multi-sensor system, based on near-infrared (NIR) absorption spectrum, rotating spectrum, Raman spectrum. The results are shown that prediction data meet the clinical accuracy.

We report on successful fabrication of GaSb-based type-I quantum well distributed Bragg reflector (DBR) lasers emitting around 2.3μm. Second-order Bragg gratings of chromium were patterned by electron beam lithography. For 1.5-mm-long laser diode, single mode continuous-wave operation with output power of 10mW is obtained. The devices show a stable single mode operation with high side mode suppression ratio.

The light scattering brings serious degradation for the object information. The conventional optical techniques cannot extract the relevant message on the object location in the scattering. In this paper, in the phase-space, the speckle characteristic with different depths has been analyzed and discussed. We utilize the phase-space-prior to locate the objects through a strong scattering medium with a learning method. Comparing with the single data-driven method, our scheme can help the deep neural network (DNN) to extract the depth information efficiently. The experimental results proved that our method is novel and technically correct with high locating accuracy. Our technique paves the way to a physical-informed DNN in locating and ranging objects through complex scattering media.

We report a multi-wavelength multiplexed setup and associated super-resolution reconstruction method in lensless microscopy, which can generate high-resolution reconstructions from undersampled raw measurements captured at multiple wavelengths. The reconstruction result of the Benchmark Quantitative Phase Microscopy Target (QPT^TM) demonstrates the resolution enhancement quantitatively, which achieves a half-pitch lateral resolution of 691 nm across a large field of view (~29.85 mm2), surpassing 2.41 times of the theoretical NyquistShannon sampling resolution limit imposed by the pixel-size of the sensor (1.67 µm). Compared with other superresolution methods such as lateral or axial shift-based device and illumination source rotation design, wavelength multiplexed avoids the need for shifting/rotating mechanical components. This multi-wavelength multiplexed super-resolution method would benet the research and development of a more stable lensless microscopy system.

Under the background of high precision machining requirements for planar optical elements, the overall structure design of four-axis special milling equipment was made, and the basic materials of equipment components were set. The precision distribution of the moving parts of the equipment is carried out for the traction of the plane optical element with high precision and high efficiency machining, so the equipment model is designed. The static simulation analysis was carried out in the two limit states of the equipment model, the basic design model and the optimal design model were compared. In the intermediate processing state, the deformation of the processing point and the driving part of the basic design model was optimized from 0.298 micron and 0.20 micron to 0.172 micron and 0.155 micron of the optimal design model respectively. The deformation of the processing point and the transmission part of the basic design model was optimized from 0.301 micron and 0.197 micron to 0.197 micron and 0.201 micron of the optimal design model, respectively.

This paper introduces the testing of annular hyperboloid mirror with 460mm diameter in the Cassegrain system. To improve the testing efficiency and meet the requirements of utilization, the study is carried out from three stages: precision grinding, precision polishing, and optical coating. In the precision grinding stage, the annular Zernike polynomial is used to fit the measured surface combining with the data measured from the coordinate measuring machine, so that it can facilitate the testing of the distribution of the surface shape deviation over the entire surface. During the precision polishing stage, a feasible Offner compensator is designed to achieve the goal of high-precision testing of the hyperboloid surface, with a measurement accuracy of RMS≤0.02λ. Also, 0.5-0.7μm and 3-5μm dual-band high reflectivity and high uniformity reflective coating is designed for the Cassegrain system requirements, the actual test reflectivity is 96.2%, which can meet the design requirements.

Freeform optics have been found in a variety of beam shaping designs. However, they are typically used to form prescribed illumination patterns on a planar surface. In this paper, we will demonstrate a ray mapping based method to design smooth freeform lenses to form complicated illumination distributions on curved surfaces. The ray mapping between the source and target is established by solving an optimal mass transportation problem which is governed by the Monge-Ampére partial differential equation. Then, the freeform lens is constructed by a geometric method based on the optimal ray mapping. Finally, the performance of the lens is verified by Monte Carlo ray tracing simulation in Zemax OpticStudio software. To show the effectiveness of the proposed method, several freeform lenses are designed as examples for a collimated light source to generate different illumination patterns on different curved surfaces. A freeform lens is also fabricated and experimented.

Non-line-of-sight (NLOS) imaging is an emerging technique, which can observe objects obscured by occluders. Thanks to the improvement of optical configurations, it is receiving growing interest from researchers. In this paper, we reconstruct both 2D and 3D images by adopting the light-cone transform and validated on simulated data. Numerical results are evaluated by structural similarity index (SSIM). The results showed the good performance of the algorithm in preserving the details of 2D image and reconstruction of 3D image. The structural similarity index of the reconstructed image and the reference image is more than 50%, the target is hence being identified. This work contributes to the construction of the real system.

Single-shot speckle projection profilometry (SPP), which can build the global correspondences between stereo images by projecting a single random speckle pattern, is applicable to the dynamic 3D acquisition. However, the traditional stereo matching algorithm used in SPP has low matching accuracy and high computational cost, which makes it difficult to achieve real-time and accurate 3D reconstruction dynamically. For enhancing the performance of 3D sensing of single-shot speckle projection profilometry (SPP), in this paper, we proposed an OpenCL-based speckle matching on the monocular 3D sensor using speckle projection. In terms of hardware, our low-cost monocular 3D sensor using speckle projection only consists of one IR camera and a diffractive optical element (DOE) projector. On the other hand, an improved semi-global matching (SGM) algorithm using OpenCL acceleration was proposed to obtain efficient, dense, and accurate matching results, enabling high-quality 3D reconstruction dynamically. Since the baseline between the IR camera and the DOE projector is about 35mm, the absolute disparity range of our system is suitably set to 64 pixels to measure scenes with a depth range of 0:3m to 3m. The experiment results demonstrated that the proposed speckle matching method based on our low-cost 3D sensor can achieve fast and absolute 3D shape measurement with the millimeter accuracy through a single speckle pattern.

In order to improve the ability of ion beam polishing efficiency and shape modification. In order to solve the problem of low polishing convergence ratio in particular, we use different beam diameters and peak removal rates of removal functions to simulate polishing process and efficiency. MATLAB tool was used to accurately fit the removal functions, and a mathematical model of ion beam simulation polishing was established to simulate the removal characteristics of ion beams with different beam diameters under different superposition spacing. A series of simulation results with different residence time distribution and residual precision were obtained by optimizing the polishing simulation algorithm, and the simulation rules were analyzed to select the most appropriate aperture and overlay spacing. Polishing simulation analysis can not only optimize residence time distribution, but also reduce machining time. It can also optimize the processing technology to achieve pre-processing prediction and achieve higher polishing efficiency while achieving the target accuracy requirements. On the basis of simulation, we polished φ120mm fused quartz flat samples with initial surface shape PV of 1079.59nm and RMS of 304.95nm. After 11 hours of polishing, the shape accuracy PV were 95.63nm, the RMS is 8.99nm, and the mean square value convergence ratio of the surface shape reaches 33.92.This simulation approach provides a effective guidance for ion beam high precision and efficiency polishing.