In the special optical system such as the infrared optical system, the compressed construction and mini module
is necessary. In this paper, a kind of compressed infrared lens design is proposed. The total length and focus length
ratio is no more than 0.6 and this type system is accessible of temperature, the key step in this design is how to
make the system actable. The parasitic light is also analyzed. The couple efficient of cool stop is 100%.
The design method and result are described for an infrared zoom system with three fields of view. Its zoom
ratio is 9, and the corresponding field of view is 3°~27°. The working waveband is from 3μm to 5μm, and its total
length is required to be no more than 400mm. The final optical system consists of 9 elements, with two aspheric
surfaces and a diffractive optical element. It achieves diffraction-limited imaging at the middle infrared waveband.
From the last result we can know using the diffractive optical elements can eliminate the color aberration and helps
to reduce the cost of the system; and using the rotated elements in the system it is easy to change the field-of-view
and satisfied the cooled detector requirements.
The results of design effort for infrared zoom systems using all reflective aspheric surfaces are described. Issues such as
the paraxial design theory and aberration balancing are discussed in detail. Two all reflective zoom optical systems are
disclosed clearly. Both of them are to be used with uncooled infrared detectors. The first design is an unobscured three
mirror zoom system without any intermediate image, and the second is a three mirror system with central obscuration
which forms an intermediate image. With the design theory further developed, this kind of systems can be designed for
cooled infrared detectors, for which cold stop matching is an important issue.
The design method and result are described for an infrared afocal zoom system. Its zoom ratio is 4, and the corresponding field of view is 3°~12°. The working waveband is from 7.5μm to 10.5μm, and its total length is required to be no more than 350mm. The final optical system consists of 7 elements, with aspheric surfaces and a diffractive optical element. It achieves diffraction-limited imaging at the far infrared waveband. Two conclusions can be drawn from the design. (1) Using diffractive optical elements in the design of an infrared optical system is an effective approach to control color aberrations, which eliminates the need to use exotic and expensive materials and helps to reduce the cost of the system; (2) Functions such as changing the field-of-view, focusing for objects at finite distances and athermalizing the system can be achieved by axially moving a single element in the system.
This paper describes the results of the design effort for a new kind of three-mirror anastigmatic system (TMAS) and its tolerance exercise. The system’s focal length is 100mm and the relative aperture is f/10, its total length is nearly f’/3~f’/3.5 and field of view (FOV) is 10° x 1°. The final optical system is a three-mirror unobscured telescope. It achieves diffraction-limited imagery at visible wavelengths. Finally, we can draw two conclusions: 1) design of unobscured optical system is still best approached using fundamental optical design principle; 2) time spent in careful modeling of fabrication, testing will result in more relaxed tolerances and a higher probability of success for the assembled system.
In the analysis of line profile in single point Laser Direct Writing process, the line profile errors will increase if we replace the exposure dose distribution by the intensity distribution of focus plane because there are differences between them. The exposure dose distribution in the photoresist is analyzed as well as the line profile after developed. The experimental results agree well with the theoretical forecast.
Based on analyzing the LC rear projective TV system, The OE (optical engine) for three penal LCoS rear projection TV system has been designed and modeled, The OE (optical engine) of LC rear projection display is the main component of the system, and it directly affects final performance, so the design of good color performance, high brightness and contrast and high optical efficient is the key of the system. From a commercial viewpoint, a compact size and light weight design makes it more competitive. LightTools software has a great many of powerful functions, such as modeling of optical system, analysis of illumination, modeling of machine structure, analysis of polarization and design of optical coating. We have used LightTools to analyses and optimize a whole optical engine of three penal LCoS projection display including illumination system, dividing and recombining of colors system, projection lens. At the end evaluated the performances of optical engine (parameters of output, uniformity, contract, resolution and so on).
Based on analyzing the LC rear projective TV system, a fly-eyes lens array telecentric illumination system has been designed, which can magnificently improve the optical performance. The modeling result by means of the LightTools software shows that the uniformity can reach (+4.8%, -6.0%). And the effective energy can be above 91%. At the same time this paper also explicates the method of coupling of illumination system and projection lens system.
This paper describes the results of the design effort for a three-mirror anastigmatic system (TMAS) and its stray light analyzing. The system’s focal length is 4000mm and the relative aperture is f/10, it’s total length is nearly f’/3~f’/4 and field of view (FOV) is 30 × 10. The final optical system is a three-mirror unobscured telescope. It is telecentric and achieves diffraction-limited imagery at visible wavelengths. After analyzing the stray light used the Light Tool software, finally We can draw two conclusions: 1) design of unobscured optical system is still best approached using fundamental optical design principle; 2) time spent in careful analyzing the stray light and a higher probability of success for the assembled system.
In the single point laser direct writing (LDW) process, there are differences between the exposure dose distribution and the light intensity distribution, and the differences will bring the line profile errors. In this paper, the equations to calculate the exposure dose distribution for the polar coordinate laser direct writing system are presented. The differences between the exposure dose distribution and the light intensity distribution are discussed. The line profile in the photoresist after development is predicted. The experimental results agree well with the theoretical forecast.
In this paper, the manufacturing and testing procedures to make large off-axis aspherical mirrors are presented. The difficulties in polishing and testing for both circular aperture and rectangular aperture mirrors are previewed, and a possible solution is given. The two mirrors have been polished by means of CCOS, the final accuracy is 25-nm rms for 770-mm x 210-mm rectangular mirror and 20-nm rms for (phi) 600-mm circular mirror. These results just meet the optical tolerances specified by the designer, and the manufacturing and testing procedures presented here show good ability to make large off-axis aspherical mirrors.
By using a binary phase grating, a lens centering system is constructed. In our system, the lens under alignment is mounted on a suitable mechanical axis that can be a spindle of precision lathe. A binary phase grating is used as a beam splitter. Laser beam after passing through the grating only ±1 orders are kept unstop, reflected back by lens surface, recombined by the same grating, and very good contrast interference fringes can be attained. When the lens together with the spindle is rotated, the interference fringes remain motionless only when the lens rotates around its axis of symmetry. If the lens rotates around an axis of asymmetry, the fringes will move. A CCD camera is used to monitor the fringes and transversal error less than a micrometer can be achieved. The interference fringes are very insensitive to vibration and environment. I the paper the theory are presented and the experimental results are given.
Using broadband hybrid diffractive/refractive optical system, an athermalized imaging system without special optical and mechanical materials, which is the prototype for space borne small CCD camera, has been designed, evaluated, fabricated and tested. The comparison with conventional optical system is presented. Also, the paper analyzes and discusses the effect of parasite orders diffraction from binary optical element as the regular `stray light' on the image quality (MTF and contrast), and proposes an approach of image processing that can compensate such image quality degradation when broadband hybrid system is used in CCD camera.
Fabrication errors and its affecting factors were analyzed for multilevel DOE in this paper. A method of Moire fringe alignment was put forth. It was proved by actual manufacturing that this way is available for aligning positioning error.
Using refractive-diffractive hybrid system in multispectral camera to compensate thermal defocus effect is considered. The paper gives the design principle, the specification and layout, calculates the system MTF of a soaking environmental temperature and pressure variation compared to the conventional design.
A new design to lock frequency in directly doubling blue lasers is presented. We employ external gratin placed on the PZT tube to feedback lock the frequency of laser diode. The spacial distribution of LD is reduced 2.1 times and spectral distribution of LD is also compressed. Stability testing of blue laser is reported too.
Binary optics element (BOE) used to correct the aberrations of zoom lens, especially to control secondary spectrum in apochromatic zoom lens, are considered. Principles and methods are presented. The advantages in improving image quality and simplifying construction are illustrated through the design example.
Based on scale diffraction theory, binary phase gratings are designed and the effect of fabrication errors on the diffraction efficiency and uniformity is discussed. The theoretical and numerical analysis shows that (0, non-(pi) ) grating is more sensitive to phase delay error than (0, (pi) ) grating. Patterning error is very complex to analyze, but we can give a maximum intensity deviation to the grating.
This paper describes integrated intelligent system MEX—! for optical zoom lens design. It consists of several sub—expert systems which coordinate work with each other. Every sub—expert system has i ts knowledge base. HEX—i applys hi erarchi cal and di stri buted control strategy. The meta system is used to coordinate the work of the sub—expert systems. Blackboard (BB) system is used as communication medium. MEX—1 system structure can also be abstracted as a general shell of an integrated intelligent system to solve complex domain problems. We also gi ye an exampi e for opti cal zoom lens desi gn.
It is well known that the ocean has enormous important for human life. The Ocean Color Imager is going to be one of the most important optical remote sensors on the ocean satellites, with missions to survey the distribution of suspended sediment, phytoplankton, and chlorophyll. The latter two items will be used to evaluate the primary productivity of ocean. China is a country with a long coastline and large territorial ocean remote sensing is very important. Changchun Institute of Optics and Fine Mechanics (CIOFM) is studying a prototype Ocean Color Imager to determine its feasibility and applications. It is expected that the visible near infrared region (0.4 - 1.06 micrometers ) Ocean Color Imager will have a spectral resolution of 10 to 20 nm, a spatial resolution of about 1 km and a global coverage period of two to three days from an orbit 700 to 900 km in height.
The main parts of the imaging spectrometer for observing ocean color (OCM system) are: the scan subsystem, the pre-position telescope, the dispersion element, and the spectrometer which should be determined according to the science requirements of ocean color observation and the correspondent specifications of the optical design. The authors analyzed the optical systems of the MODIS-T proposed by NASA/Goddard Space Flight Center and found some problems in them. Based on this the authors designed a reflection-refraction hybrid optical system by autocollimation grating. The results are better than the improved MODIS-T optical design in some points--the minimal optical MTF value of the design at the Niquist frequency is better than 0.96, the construction is much more compact.
The authors developed a zoom lens design expert system intended to operate with little user intervention. The paper emphasizes the knowledge representation, system architecture, reasoning, and control strategy of the system MEX-1.