This PDF file contains the front matter associated with SPIE Proceedings Volume 10382, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

We report on the new class of inorganic nanocomposite films with the inorganic phase hosting the polymer nanofillers made by the concurrent multi-beam multi-target pulsed laser deposition of the inorganic target material and matrix assisted pulsed laser evaporation of the polymer (MBMT-PLD/MAPLE). We used the exemplary nanocomposite thermoelectric films of aluminum-doped ZnO known as AZO with the nanofillers made of poly(methyl methacrylate) known as PMMA on various substrates such as SrTiO₃, sapphire, fused silica, and polyimide. The AZO target was ablated with the second harmonic (532 nm) of the Nd:YAG Q-switched laser while PMMA was evaporated from its solution in chlorobenzene frozen in liquid nitrogen with the fundamental harmonic (1064 nm) of the same laser (50 Hz pulse repetition rate). The introduction of the polymer nanofillers increased the electrical conductivity of the nanocomposite films (possibly due to the carbonization of PMMA and the creation of additional channels of electric current) three times and reduced the thermal conductivity by 1.25 times as compared to the pure AZO films. Accordingly, the increase of the thermoelectric figure-of merit ZT would be ~ 4 times. The best performance was observed for the sapphire substrates where the films were the most uniform. The results point to a huge potential of the optimization of a broad variety of optical, opto-electronic, and solar-power nanocomposite inorganic films by the controllable introduction of the polymer nanofillers using the MBMT-PLD/MAPLE method.

Horizontal spot size converter required for horizontal light coupling and vertical bridge structure required for vertical integration are designed on high index contrast SOI platform in order to form more compact integrated photonic circuits. Both the structures are based on the concept of multimode interference. The spot size converter can be realized by successive integration of multimode interference structures with reducing dimension on horizontal plane, whereas the optical bridge structure consists of a number of vertical multimode interference structure connected by single mode sections. The spot size converter can be modified to a spot profile converter when the final single mode waveguide is replaced by a slot waveguide. Analysis have shown that by using three multimode sections in a spot size converter, an Gaussian input having spot diameter of 2.51 μm can be converted to a spot diameter of 0.25 μm. If the output single mode section is replaced by a slot waveguide, this input profile can be converted to a flat top profile of width 50 nm. Similarly, vertical displacement of 8μm is possible by using a combination of two multimode sections and three single mode sections in the vertical bridge structure. The analyses of these two structures are carried out for both TE and TM modes at 1550 nm wavelength using the semi analytical matrix method which is simple and fast in computation time and memory. This work shows that the matrix method is equally applicable for analysis of horizontally as well as vertically integrated photonic circuit.

Over the last decade it has been demonstrated that nonlinear optical (NLO) crystals can be grown by laser precipitation in customized glasses and used for electro-optic applications. It has been further demonstrated that this novel crystal growth technique is capable of fabricating nonlinear waveguide structures, where the polar axis of the crystal is aligned along the growth direction. Femtosecond precipitation of NLO crystals in glass has the potential to be a low-cost method of creating functional optical elements. In order to realize this goal, the orientation of the NLO crystals must be carefully controlled. In the present study, a widely used electro-optical crystal, Lithium Niobate, was precipitated in 33LiO₂-33Nb₂O₅-34SiO₂ (mol%) (LNS) glass, forming NLO crystalline structures in an amorphous matrix. Glass fabrication techniques for making high quality glass, and the crystallization parameter space were explored to determine the optimal conditions for smooth and continuous crystal growth. The crystalline orientation of the precipitated lithium niobate was determined for a variety of writing conditions, and the growth technique was extended to multi-dimensional structures.

In the previous research, an optical force equation for microbubbles is derived to compute the force on a microbubble that is steered in a liquid using an optical field. To compute the total number of particles in the spherical microbubble, a tabular method is used. Although the tabular method is not complex and provides the approximate value, it is necessary to derive an equation for the precise value in computing the number of particles. This research paper has derived an equation for computing the total number of particles in the spherical microbubble. The equation provides the precise and reliable results in the computation of the total number of particles. By computing the number of particles using the equation instead of the tabular method, the reliability and precision of the optical force equation for the microbubble are increased.

Blackbody radiation of the material in high temperature has the great potential to become the light source of an optical fiber sensing system. In this paper, a blackbody radiation cavity is designed and the influence factors of light energy coupling into fiber are analyzed. Fiber Fabry-Perot sensing system based on light source of blackbody radiation has been set up and strain sensing experiment has been carried out. Results show that blackbody radiation is strong enough to support sensing of fiber Fabry-Perot sensors in high temperature, the strain sensitivity is 14.76nm / με ~ 15.63 nm / με.

In this paper, we propose the design of fiber optic refractive index sensor based on a thin core fiber, sandwiched between an input and output single mode fibers. This structure is characterized by a refractive index sensitivity about 187.98 nm/RIU (refractive index unit). In order to enhance the sensitivity, we designed a tapered single mode-thin core-single mode fiber structure where the sensitivity with different waist-diameters (90, 60 and 30 μm) is investigated. As a result, we obtained an ultra-high sensitivity of the tapered sensor about 783.19 nm/RIU in the refractive index range of 1.3346-1.3899, using sucrose and water mixture solution, achieved for a waist diameter equal to 30 μm and a taper length of 675μm.The designed structure presents the merits of high sensitivity which is 4 times higher than that of the thin core fiber modal interferometer which makes it an excellent candidate for biochemical sensing applications.

Many applications rely on the ultra-precise timing of optical signals through fiber, such as fiber interferometers, large telescope arrays, in phase arrayed antennae, optical metrology, and precision navigation and tracking. Environmental changes, specifically those caused by temperature fluctuations, lead to variations in the propagation delay of optical signals and thereby decrease the accuracy of the system’s timing.

The cause of these variations in delay is the change in the glass properties of the optical fiber with temperature. Both the refractive index of the glass and the length of the fiber are dependent on the ambient temperature. Traditional optical fiber suffers from a delay sensitivity of 39 ps/km/K. We are reducing the temperature sensitivity of the fiber delay through the application of a novel design of optical fiber, Anti-Resonant Hollow Core Fiber. The major improvement in the thermal sensitivity of this fiber comes from the fact that the light is guided in an air core, with very little overlap into the glass structure. This drastically reduces the impact that the thermally sensitive glass properties have on the propagation time of the optical signal. Additionally, hollow core fiber is inherently radiation insensitive, due to the light guidance in air, making it suitable for space applications.

This paper presents a quantitative two-dimensional (2D) analysis on high power GaN light emitting diodes (LEDs) fabricated on asymmetric micro-structured substrates. It is found that the light extraction efficiency (LEE) can be substantially improved from conventional symmetric structure to asymmetric structure. The increase of LEE is mainly dedicated to the increased surface area and better randomization on the direction of transmitted/reflected light, which enhances the escaping probability after multiple reflections. This quantitative 2D analysis lays down a solid foundation for the future quantitative 3D analysis.

Gold nanorod has generated great research interests due to its tunable surface plasmon resonance (SPR). The mechanism of the SPR effect on the enhancements of optical performance for the volume holographic polymer is investigated. The resonance wavelength is dependent on the aspect ratio of the nanorod. Theoretical model for the localized surface plasmon resonance effect are developed and simulated for the interactions between the photopolymer components and nanorods in the gold nanorod doped volume holographic photopolymer. The experimental evaluation of the material suggests a novel candidate for potential applications in high-density optical data storage and high-resolution holographic display.

Previously, we have reported measurements of temperature-dependent surface resistivity of pure and multi-walled carbon nanotube (MWNCT) doped amorphous Polyvinyl Alcohol (PVA) thin films. In the temperature range from 22 °C to 40 °C with humidity-controlled environment, we found the surface resistivity to decrease initially, but to rise steadily as the temperature continued to increase. Moreover, electric surface current density (J_s) was measured on the surface of pure and MWCNT doped PVA thin films. In this regard, the surface current density and electric field relationship follow Ohm’s law at low electric fields. Unlike Ohmic conduction in metals where free electrons exist, selected captive electrons are freed or provided from impurities and dopants to become conduction electrons from increased thermal vibration of constituent atoms in amorphous thin films. Additionally, a mechanism exists that seemingly decreases the surface resistivity at higher temperatures, suggesting a blocking effect for conducting electrons. Volume resistivity measurements also follow Ohm’s law at low voltages (low electric fields), and they continue to decrease as temperatures increase in this temperature range, differing from surface resistivity behavior. Moreover, we report measurements of dielectric constant and dielectric loss as a function of temperature and frequency. Both the dielectric constant and dielectric loss were observed to be highest for MWCNT doped PVA compared to pure PVA and commercial paper, and with frequency and temperature for all samples.

In this article we have based on the laws of physics to illustrate the enigma time as creating our physical space (i.e., the universe). We have shown that without time there would be no physical substances, no space and no life. In reference to Einstein’s energy equation, we see that energy and mass can be traded, and every mass can be treated as an Energy Reservoir. We have further shown that physical space cannot be embedded in absolute empty space and cannot have any absolute empty subspace in it. Since all physical substances existed with time, our cosmos is created by time and every substance including our universe is coexisted with time. Although time initiates the creation, it is the physical substances which presented to us the existence of time. We are not alone with almost absolute certainty. Someday we may find a right planet, once upon a time, had harbored a civilization for a short period of light years.

This paper presents an ultra-fast growth of silicon carbide crystal with the size up to 50 μm from SiC nanopowders. By using a CO₂ laser with a power of 30W to heat the silicon carbide nanopowders in a vacuum chamber, the nanopowders tends to congregate together to form larger particles first. Following the slow cooling process, the congregate formation would further transform to final SiC micro-crystals. The two types of final products grown from quenching process and slow cooling process were analyzed by SEM. The lattice structure of final SiC micro-crystal was determined to be hexagonal structure according to the XRD analysis.

A setup using fringe projection techniques to perform 3D profile measurements for transparent objects is presented. The related mathematical equations are derived as well. A fringe pattern is illuminated onto the transparent object. Fringes passing through the inspected object are then projected onto a screen. A CCD camera is employed to record the transmitted fringes on the screen. Fringe on the screen are deformed by the refractive index and the surface structure, and therefore are desirable to describe the shape of the inspected sample.

A scanning pattern projection technique for 3D shape measurements is proposed. A binary grid pattern is employed as the projected pattern. The limited depth-of-focus of the pattern projection system makes the surface on the focused area can be clearly observed. Thus, a 2D contour of the inspected surface addressed by the in-focused fringes was obtained. By assembling the surface contours with their corresponding depths, the 3D shape of the object cab retrieved.

We investigated double-clad (DC) optical fibers for high power laser applications, with concentrically co-grown ‘Yb:YAG/YAG’ crystal structure, for which ‘crystalline core/crystalline clad’ = CCCC = C4 fiber term was coined. The fibers were fabricated using a liquid phase epitaxial growth (LPE) of undoped single-crystalline YAG cladding around the 100 µm single-crystalline Yb:YAG core separately grown by a laser heated pedestal growth (LHPG) technique. Laser testing of the low-loss C4 fibers with direct diode-clad-pumping at 969 nm has demonstrated over 40 W of core-guided (NA ≈ 0.025) multimode laser output at 1030 nm with over 60% slope efficiency.

In this paper, we present a novel large capacity (a 1000+ channel) time division multiplexing (TDM) laser beam combining technique by harnessing a state-of-the-art nanosecond speed potassium tantalate niobate (KTN) electro-optic (EO) beam deflector as the time division multiplexer. The major advantages of TDM approach are: (1) large multiplexing capability (over 1000 channels), (2) high spatial beam quality (the combined beam has the same spatial profile as the individual beam), (3) high spectral beam quality (the combined beam has the same spectral width as the individual beam, and (4) insensitive to the phase fluctuation of individual laser because of the nature of the incoherent beam combining. The quantitative analyses show that it is possible to achieve over one hundred kW average power, single aperture, single transverse mode solid state and/or fiber laser by pursuing this innovative beam combining method, which represents a major technical advance in the field of high energy lasers. Such kind of 100+ kW average power diffraction limited beam quality lasers can play an important role in a variety of applications such as laser directed energy weapons (DEW) and large-capacity high-speed laser manufacturing, including cutting, welding, and printing.

Various rare earth doped single crystal YAG and sesquioxide fibers have been drawn using a state-of-the-art Laser Heated Pedestal Growth system. All crystalline core/clad fibers where thermal and optical properties are superior over glass based fibers have been successfully fabricated using various crystal growth and deposition methods. We report on the various fabrication methods, optical characterization of these clad fibers.

This paper presents a nanosecond speed KTN varifocal lens. The tuning principle of varifocal lens is based on the high-speed refractive index modulation from the nanosecond speed tunable electric field. A response time on the order of nanoseconds was experimentally demonstrated, which is the fastest varifocal lens reported so far. The results confirmed that the tuning speed of the KTN varifocal lens could be significantly increased by avoiding the electric field induced phase transition. Such a nanosecond speed varifocal lens can be greatly beneficial for a variety of applications that demand high speed axial scanning, such as high-resolution 3D imaging and high-speed 3D printing.

Arrayed waveguide gratings (AWGs) are typically used by the telecommunications industry as (de)multiplexers. However, recently they have successfully been demonstrated as integrated sensors for applications such as biomedical and astronomical spectrographs. Unfortunately, advancement is generally stalled by development costs and time; or restricted to spectral regions covered by off-the-shelf lithographic produced AWGs. To broaden the potential applications of integrated spectrographs employing AWGs, we utilise the femtosecond laser direct write technique as a rapid-prototyping platform for fabricating AWGs. The AWGs fabricated operate at 633nm, have a free spectral range of 22.4nm, resolution of 1.35nm, resolving power of 468.7, a throughput of 11.47% across the 5 main orders, and 3.97% in the central 28th order. This mask-less process enables complete design freedom, takes approximately 2hours from completed design to finalized device, thus facilitating design feedback to easily fine tune the device specifications. In some applications multimode fibres are used for efficient light collection, thus leading to large losses when coupling into single mode devices such as AWGs. A solution is to utilize a 3-dimensional photonic lantern. A photonic lantern converts multimode light into multiple single-mode waveguides that can then be individually launched into an AWG. While the AWG is only a 2-dimensional device the laser direct write technique enables 3-dimensional fabrication. Thus supporting the integration of a photonic lantern and AWG into a single monolithic chip, removing coupling losses while increasing the functionality of the AWG. Currently we have demonstrated the integration of a 3 port photonic lantern.

A one-shot profilometry for surfaces with color or reflectivity discontinuties is presented. It uses binary-encoded pattern to illuminate the inspected object and a monochromatic camera to observe the deformed fringes at another view angle. The encoded pattern provides additional to identify the fringe order. For spatially isolated objects or surfaces with large depth discontinuities, unwrapping can be identified without ambiguity. Even though the surface color or reflectivity varies rapidly with position, it distinguishes the fringe order as well.

A fringe projection profilometry is presented. It uses the phase-shifting technique perform the phase-extraction and use the ternary-encoded patterns to identify the fringe orders. Only five-shot measurements are required for data processing. Experiments show that absolute phases could be obtained with high reliability.

A magnetic field sensor based on a Mach-Zehnder interferometer with standard single mode fiber (SMF-28) is proposed. Here, the MZI was developed by using tapered optical fiber technique. Moreover, the Mach-Zehnder interferometer is manufactured with two tapers, with a core diameter of 25~40 μm and a length of 5 mm, and a separation between the tapers about of 4~6.5 cm. The MZI was covered by a fluid with magnetic proprieties. Performing experiments with magnets, coils and transformers, hoping that the proposed sensor offers a good option to measure the magnetic field in electrical devices.

Stabilizers are added to nitrate ester-based rocket motor propellants to form a stable product. The products added to stabilize the propellants react with NOx and are gradually exhausted over a period of time. In this paper, we demonstrate the efficacy of Raman spectroscopy technique for nondestructive, inexpensive, and rapid evaluation and monitoring of the depletion of rocket motor propellant stabilizers. Preliminary results show that concentrations as low as 0.1% of both MNA and 2-NDPA dissolved in DMSO (Dimethyl sulfoxide) can easily be detected at 1 second integration time using a 785 nm wavelength Raman system. In addition, MNA concentrations between 0.37% and 0.54% are detected in propellant samples containing energetic constituents using a 60 second integration time.

This paper presents a high-contrast electro-optical modulator with record-breaking amplitude modulation index of 27 dB and forward loss of < 3 dB at 1.5 μm. The high contrast is achieved by utilizing slit and surface plasmon polariton resonances in an array of gold lines filled with a phase change material (Germanium Telluride-GeTe). Stacking multiple layers of the phase change plasmonic grating enabled development of the high-index modulator in chip scale dimensions at telecommunication wavelength. Coupling the optical modes of multiple layers results in such a high contrast when GeTe goes through crystallographic phase transition. Phase transition through joule-heating is achieved by employing a matching circuit.