This PDF file contains the front matter associated with SPIE Proceedings Volume 10841, including the Title Page, Copyright information, Table of Contents, Introduction and the Conference Committee listing

The box-like optical filter is one of the most important key optical switching components in the dense-wavelength division-multiplexing (DWDM) fiber-optic communication system and the intelligent optical network. The integrated high-order silicon microring resonators (MRRs) are one of the best candidates to achieve the box-like filtering spectrum response. In general, the spectrum response rectangular degree of the single MRR is very low, so that it can not be used in the DWDM system. Using the race-track high order MRRs, the bandwidth of flat-top pass band, the out-of-band rejection degree and the roll-off coefficient of the edge will be improved obviously. In this paper, a box-like optical filter based on the race-track high order MRRs with uniform couplers is presented and demonstrated. Using 15 coupled racetrack MRRs with 10 μm radius, the 3 dB flat-top pass band of 2 nm, the out-of-band rejection ratio of 30 dB and the rising and falling edges of 48 dB/nm are realized successfully.

Optical fiber sensor based on extraordinary optical transmission (EOT) phenomenon is widely used in chemistry, biomedicine and other fields for its intense near-field enhancement effect and high sensitivity of dielectric environment. However, processing periodic nanohole arrays structure on the fiber end face requires complicated process or expensive microfabrication equipments, which limits the development of optical fiber sensor based on EOT phenomenon. Striving to solve this problem, this paper proposes the template transfer method to process metal periodic nanostructures on the fiber end surface, and further examines the influence of excitation angle on the localized surface plasma resonance(LSPR) and surface plasmon resonance(SPR) through grinding the fiber end surface into sloping structures with different angles. The experiment results show that when the Angle is 7°, resonance excitation of fiber sensor with periodic nanohole arrays structure performs the strongest, as well as sensors achieving optimal sensing ability.

As an optical element, diffraction grating is of considerable importance in many research fields. In this paper, Fourier analysis method is used to analyze the Fraunhofer diffraction phenomena of plane and convex holographic gratings under various conditions. Based on the transmittance function, the law of complex amplitude distribution, intensity distribution and spectral distribution on the diffraction screen is derived. For the planar and convex holographic gratings in the spectrometer design, the inherent laws of optical phenomena can be understood more deeply. In particular, the convex holographic gratings are analyzed as a combination of amplitude type plane grating and phase type spherical mirror, rather than being considered separately in most literature.

Effective measurement of the surface and thickness variation of thin films are important to achieve a special function and better performance for a coated optical device. In this research, we propose a new incoherent technique named Fourier transform-based structured illumination microscopy (FTSIM) to detect the surface topography and thickness distribution. In this technique, a sinusoidal fringe pattern produced by digital micro-mirror devices (DMD) is projected onto the sample. The modulation estimation which depends on the surface and thickness of thin films is obtained by two-dimensional Fourier transform algorithm. Further, separating the reflected signals from the film boundaries, the surface finish of the film, as well as a film thickness map, can be achieved at the same time. With this method, only one pattern is required to determine the modulation value of a whole field. The measurement system is relatively simple and only an ordinary objective is enough to achieve imaging of the sample. Both theory and experiments are conducted in detail to demonstrate that the availability of this method.

With the rapid development of lithography technology, the processing width of lithography line is up to 10 nm. The tiny defects on the surface of substrate and particles attached to the surface have a great influence on the quality of lithography, especially the surface plasmons lithography, which requires the gap between the substrate and the mask should be controlled within dozens of nanometers, since the surface defects and particles seriously affect the quality of the surface plasmons lithography. Substrate detection device in foreign countries is costly, and the results detected by optical microscopes and electron microscopes can’t meet the requirements of the current experiment. Therefore, a set of scattering detection device needs to be developed in order to meet the requirement of the defect detection of the substrate surface.

The microscopy assisted by dielectric microspheres has emerged as an effective way to improve the imaging resolution of conventional optical microscope. The photonic nanojet(PNJ) is simulated by software, and super-resolution imaging experiments are carried out successfully. The results show that the silica(SiO₂) microsphere with low refractive index can visualize a grating containing 139-nm-width lines with an interspacing of 139 nm under visible light illumination when it is partially immersed in alcohol. However, the barium titanate glass(BTG) microspheres with high refractive index can achieve super-resolution imaging only fully immersed in alcohol.

In order to realize the superresolution imaging with a telescope optical system, a two- dimensional polynomial function phase pupil filter with a high strehl ratio is designed, and its improvement for the light distribution around the focal point of the optical imaging system is demonstrated. The result of the theory analysis shows that, when the filter is added into the system, the system optical resolution is increased 1.33 times, and the strehl ratio is 0.75 time as much as that of the system without this pupil filter. The performance of two-dimensional polynomial filter is compared with the other typical phase pupil filters, including the three-zone, the four-zone and the one-dimensional polynomial phase filter. The comparison results show that the strehl ratio of the two-dimensional polynomial filter is the highest in these filters, and the transverse superresolution ratio of this filter is next only to that of the four-zone filter. But the strehl ratio of the four-zone filter is too low to be applied into the telescope.

In this paper, we propose a dielectric cylindrical lens and a dielectric spherical lens with dual polarity operating at visible frequencies. Composed of an array of nanofins with high aspect ratio as phase shifting elements, the designed dielectric dual-polarity lens have higher scattering efficiency and polarization conversion power than plasmonic dualpolarity lens. The phase variation from 0 to 2π is determined by adjusting the orientation angle of the individual nanofins according to the PB phase. By controlling the helicity of the incident circularly polarized light, the positive and negative polarity are interchangeable in one designed metalens. We demonstrate the broadband metalens possess a wavelength controllable focal length with incident wavelength from 488 to 740 nm. The dielectric dual-polarity metalens may open a new avenue for advanced research and applications in focusing and imaging devices, angular-momentum-based quantum information processing and integrated nano-optoelectronics.

Bioinspired nanostructures have attracted increasing attentions and found widespread applications in various fields including material, chemical, mechanical and optical engineering because of their unparalleled physical advantages¹. Honeycomb, a kind of porous structure, owns unique structure features, which enable its properties of low density, high mechanical strength, and high-energy-storage capacity². The high quality of metal honeycomb structure with high uniformity, smooth metal surface, high-aspect-ratio sidewall and sharp corners of the triple junction is useful for plasmonic functional devices. Inspired by the building process of natural honeybee combs, we proposed an unconventional nanofabrication technique to produce high-quality gold nano-honeycombs with high-aspect-ratio (>10:1) and thin (<20 nm) sidewalls. As one of the important applications, the refractive index (RI) sensing behavior of the gold nano-honeycomb arrays was modeled and investigated numerically based on the surface plasmon polariton effect. The simulation results show that, in near-infrared region, the RI sensitivity is about 850 nm/RIU, which is approaching the theoretical limit³.

We propose a new pixel design which has one slit electrode for 806 ppi resolution. The pixel design facilitates a reduction of disclination area in the pixel and enhancement of aperture opening ratio. We also propose a new photo spacer design which has smaller shading area for VR. This design improves the problem of dark spots caused by the fixed shading area. As a result, we have demonstrated a high transmittance, good image quality without dark spots and high product yield on 2.8 inch 806 ppi panel.

This paper reviews the research progress of liquid crystal optical phased array (LCOPA) devices in space laser communication applications. According to the constraints of space applications and system requirements, in the design and key technologies of array devices, the research progresses on the implementation methods such as wide-point range, large-aperture optical aperture, short response time, and space environment adaptability are emphatically introduced. In introducing the wide beam pointing range, the beam control method and the digital concatenation scheme are mainly described. In the study of large aperture, the area filling module and the area selection module are separately analyzed. And comparatively expounded the realization of sub-millisecond order rapid response of liquid crystal materials, and finally gave the United States Air Force laboratory's research on the liquid crystal optical phased array device irradiation environment adaptability research results.

Unlike traditional imaging, the light field imaging can obtain location and direction information by one shot, which makes the dynamic three-dimensional shape measurement possible. Firstly, this paper establishes a pixel light field model, and calibrates the measurement system, which lays the foundation for light field refocus. Then proposes light field 3-D shape measurement method based on digital focus distance measurement and appropriate sharpness evaluation function. Meanwhile, hardware module used in dynamic three-dimensional shape measurement based on light field imaging is designed, which is responsible for real-time collection and processing of the light field images and greatly improves the reconstruction speed of the images. Finally achieve light field 3-D shape measurement. The experimental results are present to demonstrate the feasibility of this technique.

With the rapid development of switchable devices for the K-band (≤40GHz) frequency range, there is a strong demand for liquid crystals (LCs) exhibiting high birefringence, low melting point and low dielectric loss ,low viscosity and good miscibility. The novel series of difluorovinyl liquid crystal compounds with Δn value around 0.4, relatively low melting point which can be as low as 34.4℃ were designed and synthesized. Comparing the difluorovinyl liquid crystal compound with isothiocyanide-containing liquid crystals, UV absorption test and dielectric loss test analysis at high frequency were performed. Difluorovinyl liquid crystals were prepared into a mixed liquid crystal material for high-frequency dielectric loss test and viscosity performance test analysis at different temperatures to explore its low temperature viscosity dependenceon temperature. The experimental results show that the difluorovinyl liquid crystal compounds not only have higher Δn value and lower melting point, but also have lower dielectric loss at high frequency and low temperature viscosity, which can improve the low temperature viscosity performance of liquid crystal materials.

With the improvement of the performance of electro-optical sensors and computer performance, lensless digital in-line holography has been studied and applied widely. However, the resolution of the digital in-line holography system are limited by pixel size and influenced by the twin image. To solve the problem, we proposed a resolution enhancement method, which collects two holograms with different sample-to-sensor distance. The reconstruction is based on Gerchberg–Saxton iteration algorithm, using two normalized and interpolated holograms. We used two prior constraints in the iteration process according to the iteration algorithm for phase retrieval: intensity of the two normalized holograms and the non-negative absorption of the sample. In this method, the interpolation operation before phase retrieval can digitally reduce the sampling interval, and the interpolation point will be optimized with the iteration process. We simulated the resolution enhancement method, and the results of the simulation show that the resolution and image quality of lensless digital in-line holography can be effectively improved.

Gas flow distribution of reaction chamber of reactive ion etching (RIE) etcher is usually considered to be a main factor in determining both the plasma distribution and etching uniformity. Based on the continuum fluid and heat transfer models of the commercial software, Fluent(Ansys), the gas flow distribution of the reaction chamber was simulated. And then the spatial distribution profiles of the pressures above the electrode surface under the different mass flow (50～250sccm) inlet conditions , and the influence of the different GAP (L = 0.03～0.06m) of the chambers on the gas flow uniformity were discussed. The result shows that the pressure distribution above the electrode has the character which the pressure is higher in the center of the electrode and lower at the edge and increases with the rise of the mass flow of inlet. And the uniformity of the gas flow distribution is enhanced with the rise of the GAP of the chamber.

The structured illumination microscopy fills an unmet need for minimally invasive tools to image micrometer and nanoscale structure. However, conventional structured illumination super-resolution methods require precise phase shift of the illumination pattern, which leads to an inefficient image reconstruction process and a complicated imaging system. To solve these problems, we propose a novel image reconstruction method using only two image to acquire the frequencies beyond the diffraction limit. This method has an efficient image post-processing, which obtains extended frequencies without accurate estimation of phase-shifting. The related simulations and experiments are carried out to demonstrate the feasibility of this method.

Interferometry with computer-generated hologram (CGH) has been widely used in the field of precision optical testing and metrology. CGH can easily generate reference wavefronts of any desired shape by controlling the phase of the diffracted light. Traditional CGH is made by etching a specific pattern on a substrate, whose cost is extremely high and the phase of the diffraction wavefront is sensitive to the changes in etching depth. Based on photoalignment technology, liquid crystal (LC) can be fabricated into LC-CGH. The LC phase modulation elements made by this technology have the advantage of low cost and high accuracy. The existing phase modulation elements based on photoalignment technology are mostly qualitative phase controller, such as LC-grating and LC-wave plate. They are rarely used in high precision applications. In the field of optical testing, the high precision of diffractive wavefront of LC-CGH is critical. The wavefront changes due to phase retardation in adjacent areas of LC-CGH is affected by the flatness of the LC film. Therefore, it is essential to keep the surface of the LC-CGH flat. In this paper, we measure the surface flatness and the diffraction wavefront of the LC-CGH film to verify the feasibility of LC-CGH in optical testing. First, we introduce photoalignment technology and analyze the principle of LC-CGH. Second, we measure the surface flatness of LC-CGH. In the end, we evaluate the transmitted diffraction wavefront. The results can provide guidance for the LC-CGH process improvement.

Various optical imaging devices have been significantly developed as commercial products including digital cameras, smartphone displays, and three-dimensional microscopes in the electronic industry until now. Such a rapid development makes many people expect more advanced devices which may be not only multifunctional but also smaller and lighter. However, we cannot achieve it only by scaling down conventional optic systems due to the limits of inherent volume needed in classical optic parts. Nanophotonics can be a potential candidate to overcome the intrinsic problem. In particular, plasmonic and metasurface nanostructures have been briskly studied in recent years because they are able to control input lights within a few hundred nanometers of a thin layer. Here we introduce some representative cases of them for optical imaging. We firstly propose a cavity-aperture, which is comprised of a cavity and a metal nanoaperture, to change the color and intensity of the light transmitted through a single pixel. Because a cavity organizes various lights having different wavelengths and a nanoaperture spatially selects one of them without a serious distortion of a light field distribution, we can extract a light with a specific wavelength and amplitude using the cavity-aperture. Some metasurface nanostructures are also suggested for a broadband polarimeter, circular polarizer, directional switching, and holographic imaging. They are useful in dramatically miniaturizing optical devices due to their thin and compact sizes. We expect these plasmonic and metasurface nanostructures have a potential for advanced portable imaging systems.

With the deepening of the application of photoelectric imaging technology, the measurement of image sensors and imaging system parameters becomes important. The non-uniformity of photoelectric response of image sensor pixels is an important index of the image sensor, which directly affects the imaging quality of the photoelectric imaging system. When measuring the non-uniformity of an image sensor, a widely applied method currently uses an integrating sphere to obtain a surface light source with a uniform irradiance, so as to eliminate the influence of non-uniformity of the light source on the measurement result. Take the plane at a certain distance from the exit of the integrating sphere as the surface light source. Taking into account the needs of practical use, this article added a cylinder as a darkroom between the exit surface of the integrating sphere and the surface light source. In order to obtain better uniformity of light source, the inner surface structure of the cylinder adopts a fine thread structure design. The process and conclusion of the simulation research of various parts of the system using optical simulation software ASAP are described in detail. The simulation studied the effects of the opening ratio of the integrating sphere, the length of the cylindrical darkroom, and the structural parameters of the fine thread on the uniformity of the output light source. The system was implemented in the laboratory and the measured results show that the light source produced by the system achieves the expected uniformity.

Beaconless spatial acquisition contribute a lot to designing a more integrated and smaller laser communication terminal for optical inter-satellite communication. In this paper, we present an analytical model of beaconless spatial acquisition on the influence of vibration. Two kinds of scan methods are analyzed, which are single scan and multi-scan. The analytical expressions of the acquisition probability of single scan and the mean acquisition time of multi-scan are derived. Numerical simulation and Monte Carlo experiment are adopted. The simulation results show that the acquisition probability of single scan asymptotically approaches a constant value with the increase of vibration levels and becomes higher if the beam divergence is increased, but the scan beam gain decrease at the same time. So, the overall acquisition link margin should be sufficient when increasing the beam divergence. What’s more, the accurate location of the target satellite has a great influence on the acquisition probability. When it comes to the multi-scan mode, the shortest mean acquisition time is got at the vibration level of 40μrad. And, the increase of multi-scan times can overcome the influence of vibration efficiently. The conclusions above can give some guides to the design of beaconless spatial acquisition system.

Camera calibration is vital in inverse Hartmann system for measuring surface shape of large aperture plane mirrors. It directly affects system accuracy. Through calibration, the internal and external parameters of camera can be acquired. In order to increase the accuracy of camera calibration, this paper selects dot matrix pattern suitable for our system as calibration plate and applies centroid detection algorithm to extract position of feature points. The impact of number and diameter size of dots on camera calibration has been analyzed. Through experiment, the repeatability of the centroid detection algorithm for dot matrix reaches 0.004 pixels, while corner extraction algorithm for checkboard is only 0.007 pixels. It indicates that using dot matrix pattern to calibrate camera is better than using a checkboard in inverse Hartmann system.

Optical window working under differential pressure condition could deform and deteriorate optical quality. Therefore, an optical window manufactured and measured under zero differential pressure would induce transmission wavefront aberration, when it works under differential pressure condition. A new processing technology requires the optical window to be manufactured and measured under a given differential pressure condition which is equal to the actual working differential pressure of the optical window. The loop of manufacturing and measuring goes on, until the final measuring result satisfies requirement. The completed optical window could repeat measuring result when it works at the same differential pressure condition.

It is necessary to fit the discrete sampling value of the optical element surface obtained by measuring equipment, because the results of fitting are useful for manufacturing and optical design. The commonly used fitting methods are X-Y polynomial approximation, Zernike polynomial approximation and radial basis function (RBF) approximation. Compared with others, radial basis function is more suitable to fit the complex optical surface. However, the further improvement of fitting accuracy and cost are limited by the fixed shape parameter of the classic RBF approximation. In this paper, we propose the sparse radial basis function approximation with spatially variable shape parameters to fit discretely sampled optical surfaces. Our main purpose is to improve fitting accuracy and to reduce computational cost. Then, we analyze the impact of the spatial distribution of RBF nodes on fitting. Finally, we compare the accuracy and cost between the classic RBF approximation and the sparse RBF approximation with spatially variable shape parameters by fitting various complex surface.

Fecal microscopic examination is a routine examination item to determine whether the digestive system is normal by analyzing formed elements. Traditional method is that doctor uses microscope eyepiece to observe sample smears. The efficiency is low, and examination results depend on doctor's experience level. Therefore, intelligent identification of formed elements is the main development direction of current fully automated fecal instruments. Unlike blood or urine samples, human fecal samples contain a lot of impurities, and sample stratification phenomenon is serious. So image quality assessment methods are difficult to find the sharpest image, affecting effectiveness of intelligent identification algorithm. In this paper, the microscopic image autofocus technology for human fecal samples is studied and divided into two parts: location and photographing. In location process, we use SMD algorithm to determine sample photographing interval. In photographing process, microscope platform zigzagged move in the interval to obtain each view's successively image sequences of different focal lengths. In order to accurately find the sharpest image in image sequence, we compared the difference between human eyes with 31 types of no-reference image quality assessment methods based on entropy, gradient, color, edge, contrast, similarity, and transform domain. Finally an improved Local TV algorithm was chose. Experimental results show that the improved Local TV algorithm is insensitive to changes in sample concentration with good robustness, and the accuracy rate can reach 94.26%. Our experimental results have some reference value for other focusing problems of complex microscopic images.

At present, most of the measurement of complex surface volume is based on contact-type manual measurement. The design system uses non-contact photoelectric method to measure the volume of the object. The laser is used to position the center, the object is placed on the rotating stage, and the double camera is captured by the industrial camera. , based on Matlab image processing, calculate its volume, its high precision, speed.

The middle and upper atmosphere is an important part of atmosphere of the earth. In this region, there are many photochemical phenomena and dynamical processes. One of the photochemical phenomena is airglow. When excited atmospheric molecule or atom transmits to lower level, the light with some wavelength will emit. The light is referred to as airglow. Airglow is therefore a powerful tool in investigations of atmospheric composition, temperature, and density in the emission region, and mass and energy movements to or from this region. Tracing the airglow emission, all-sky airglow imagers are widely used for imaging the atmospheric airglow. The characters of the imager are: wide field of view, fast, high resolution, low cost. This paper systematically studies the basic principle of the imager, completes the calculation of the key parameters, designs the optical system structure of the imager and optimizes the system image quality to obtain an ideal design result. The main contents can be list as follow. All-sky imaging technology records the optical phenomena in the 180° range above the ground plane with imaging and storage media. Use the fisheye lens to realize the 180° of the field of view. Different airglow layers correspond to different radiation peak heights. In order to obtain the atmospheric airglow signal at a certain height, it is necessary to filter the airglow radiation of different bands. The intensity of airglow information using narrow-band filter extraction feature height region of the upper atmosphere. High-sensitivity CCD were used to record all-sky airglow intensity distributions. The system consists of fisheye lens, telecentric imaging lens, filter, imaging lens and CCD. Through the analysis of recorded images, obtained observation data of regional atmospheric fluctuations of airglow height. The central wavelength of the imaging system is 630.5 nm, the bandwidth is 2 nm, the field of view is 180° the focal length is 5 mm, and the relative aperture is 1:1.9; The modulation transfers function (MTF) is more than 0.75 at the Nyquist spatial frequency of 37 lp/mm. The root-mean-square (RMS) radius of spot diagram is less than half of the pixel. 80% of the energy is enclosed in a pixel, and the uniformity of image illumination is 89%. The design requirements are satisfied. And based on the final design, the lens is simplified and the glass material is simplified. Finally, optimization of tolerance analysis is used to guide actual production. The final system structure compact, low cost, high resolution, suitable for airglow atmospheric radiation detection.

The liquid crystal phase shifter integrates the technologies of the liquid crystal display and radar antenna. It belongs to a brand-new interdisciplinary research field. The traditional leakage rate test method of electronic components is not suitable for the liquid crystal phase shifter. The liquid crystal phase shifter and liquid crystal display have similar structures and they are sealed by sealant, so, this article adopts the saturated vapor experiment and liquid crystal display material physical properties test method to make a theoretical research and experimental verification for the leak rate of the liquid crystal phase shifter. In this paper, we set up a kind of theoretical model for the liquid crystal phase shifter leak rate test and realize the actual measurement for the theoretical model. The test results comply with expected judgment, which shows that the theoretical model works, and the test results have actual guiding significance for the material and technological selection for producing liquid crystal phase shifters.

The wave-front phase recovery method is a method of numerically calculating the phase distribution of the wave-front by measuring the field intensity distribution of the emission field. Because of its easy operation, high accuracy of inversion and high precision, it has received great attention and extensive application in the free-form surface shape in modern optics detection, telescope primary, secondary mirror misalignment detection and adjustment, beam shaping and other fields. This article briefly describes several different classical methods for restoring the wave-front phase, such as the GS algorithm, HIO algorithm, and PIE algorithm in the iterative method; The transport of intensity equation (TIE)method in the non-iterative method. Then analyzed their respective advantages and disadvantages, at same time put forward personal opinions on the current deficiencies and the future direction of development.

In order to make the system design meet the requirements of practical ghost imaging, the impact of mechanical vibration on the ghost imaging is analyzed. In ghost imaging system, the light field modulated by a digital micromirror device (DMD) is used to illuminate the target and the transmission or scattering light is detected by a single pixel detector. The target is reconstructed by combining the results of the detector and the intensity distribution of light field, so the modulation matrices of light field play a vital role in ghost imaging. By considering the form of imaging system to vibration and taking the modulation transfer function as an evaluation function, this paper quantitatively analyzes the impacts of various forms of mechanical vibration on the intensity distribution of light field. Combining engineering practice, several solutions are proposed to reduce the impact of vibration on the imaging quality. The results of simulation and experiment indicated that the analysis is correct and usable.

A full aperture rapid polishing process (RPP) have been developed for batch producing high-precision large aperture optical flats required in some extreme application, such as high power laser, extreme ultraviolet lithography. Combining the theory of ultra-precision machine and chemical mechanical polishing, RPP can polish out the large aperture flat optical components in several hours or less. The material removal rate of fused silica component can be enhanced to ≥12 μm/h in RPP, which polishing efficiency is more than ten times of traditional pitch polishing process. The surface roughness also can be down to 0.3nm (RMS). Through several process improvements, the surface figure is determinately controlled, and subsurface damage can be quickly removed and suppressed. At last, high accuracy optical components can be obtained with high flatness (sub-micron), super smooth (sub-nanometer), and near-zero defects (SSD density ≤0.02 def/cm² ).

According to the requirements of the military optoelectronic system for the application of the reflector, optical processing experiments were carried out on the SiC_p/Al coating nickel phosphorus alloy plane mirror; The optical properties of the SiC_p/Al and several commonly used optical materials were compared; The turning test and polishing test of uncoated nickel-phosphorus and nickel-phosphorus-coated aluminum-based silicon carbide were carried out, the optical processing of φ150mm SiC_p/Al coating nickel-phosphorus alloy plane mirror was realized, and the high quality and high precision optical surface was obtained. The RMS value of surface accuracy was 1/27λ(λ=632.8nm), The surface roughness Ra was better than 3.3nm, which confirmed the feasibility of using SiC_p/Al composites in military optoelectronic systems and met the requirements of precision of the reflector.

The laser beam shaping system which can convert Gaussian beam to flat-top beam has been widely applied in laser illuminating, laser materials processing and laser medical treatment, etc. For the application of laser illuminating, a laser beam shaping system with simple structure and high efficiency was developed, which used two aspherical lenses to convert the 2 mm waist diameter Gaussian beam to a flat-top beam. To achieve a long-distance illuminating for different object positions, the shaped laser beam divergence angle is required variable. Therefore, a continuous zoom lens which had the zoom ratio of 18.4:1.04 was added to the front of the aspherical lenses. By moving the axial positions of the zoom lens, the continuous change of the beam divergence angle can be achieved. With the aid of ZEMAX software, this laser beam shaping system was simulated and optimized. The simulation results showed that the beam divergence angle can be continuously changed in 1°~18°, while the laser facular area energy distribution keeping uniform of 5m, 45m and 65m illuminating distances, which can satisfy the different long-distances laser illuminating requirements.

The ghost reflections can cause spurious fringes in the interferograms and lead to error in the measurement. So it is necessary to evaluate the influence of the ghost reflection spot for a correct interpretation of interferograms. In this paper, the ghost reflections of testing long focal length lens with computer-generated hologram (CGH) are investigated and geometrical model is established to obtain an expression for the size of the ghost reflection spot. Moreover, simulations and experiments are carried out by studying the ghost reflections of the long focal length lens in Shenguang III system.

In order to study the mist phenomenon on phosphate glass, the chemical composition of the hydrolysis layer on the glass surface of phosphate glass was investigated. The solid and liquid components of the used slurry and the surface composition of polished phosphate glass were tested. The experimental results show that the SIMS test results show that the content of K does not change with depth, and the content of Mg, Al, Nd firstly increases with depth and then tends to be gentle; K element does not participate in chemical reactions during polishing, just simply mechanical removed; but Mg, Al, and Nd elements are not only mechanically removed but also participate in chemical reactions and are precipitated as ions, which is consistent with the XRF test results. It is proposed a new substance generated on the surface of phosphate glass during polishing process, a hydrolysis layer formation model was proposed. The mist phenomenon is related to the hydrolysis layer, which is different from the substrate material and properties (density, light reflectance, etc.). So different scattered light is seen and the thicker the hydrolyzed layer, the stronger the scattered light. Moreover, the severity of mist is related to the thickness of the mist layer, and the thicker the thickness, the more severe the mist.

Broadband sources have been suggested for use in the interferometric measurement for which cannot easily generate interference fringes with good contrast unless the optical path difference (OPD) is very small. This leads to another problem: how to get the equivalent wavelength of a broadband light source. For a monochromatic source, the OPD between adjacent fringes is one wavelength; but for a broadband light source which has a variety of wavelengths of light, we need to know which wavelength the OPD between adjacent fringes is equal to. The distribution of the Power Spectral Density (PSD) of the broadband source has a great influence on the value of the equivalent wavelength. For a symmetrical PSD, the equivalent wavelength is its center value; for a non-symmetrical PSD, the equivalent wavelength is not a fixed value which is related to the fringe order. For high-precision interferometry, the equivalent wavelength of such a source must be calculated precisely. In this paper, a formula for the equivalent wavelength of a non-symmetrical PSD of a broadband source is deduced. Because of the complexity of the formula, the relationship between optical path difference and equivalent wavelength is not very intuitive so that a lot of simulation calculations have been done. According to those simulation calculations: the equivalent wavelength of the zero-order fringe is the centroid wavelength of the broadband spectrum; within a range of OPD and with the increase of the fringe order, if the peak wavelength of the spectrum is greater than the centroid wavelength, the equivalent wavelength will increase; if the peak wavelength is less than the centroid wavelength, the equivalent wavelength will decrease; the narrower the spectral bandwidth is, the less obvious the change is.

Optical anti-reflection coating is one of the important components of high-energy, high-power laser systems. Under laser irradiation, it is most likely to be destroyed. In this paper,three different inhomogeneous coatings were designed without changing the target transmittance, they were differently graded. In order to further analyze the relationship between different graded-index anti-reflection coatings and laser-induced damage threshold, the transmission spectrum and electric field distribution of graded-index anti-reflection coatings are studied. First of all, the average transmittance of the coatings in the visible region are not less than 99% , then three different inhomogeneous coatings are graded into different layers . When the number of gradient layers increases, the results show that the transmittance and the electric field intensity of substrate and coating interface layer does not change much, the electric field intensity at the interface between the air and coating first increases and then decreases, the sum of interfaces electric field intensity increases continuously.

In order to meet the requirement of miniaturization, high image quality and large field of view of monitor lens, based on the characteristics of monocentric lenses, and the development of curved image sensors, we designed a monitor lens optical system and all refraction surfaces and its curved image surface have the same spherical center. The monitoring optical system's FOV is 140°, the focal length is 7.88mm, the F-number is 1.50, and the total length is 14.47 mm. The monitoring optical system is up to 11-megapixel. The final design result shows that the MTF value is closed to the diffraction limit in the central field of view and the 0.7 field of view, and is greater than 0.59 at all fields of view. The RMS radiuses of different fields of view are all less than 1.1 μm . It can be clearly seen that the aberrations of each field of view are well controlled from the quantitative analysis of the transverse ray fan plot. The monitor lens has good performance in quite a large FOV with a miniaturization structure.

To meet the needs of the virtual reality market,use ZEMAX to design a compact panoramic lens.There are two fish-eye lenses in the system which works in visible light range,the field of view of lens is 200 degree and the F number is 2.8. A prism is added to the lens group to achieve a 90 degree turn of the rear lens group and then a 360-degree panoramic camera system is constructed by combining optical paths.This method effectively reduces the system volume.For the image sensor, Sony’s IMX159 chip is used, with a resolution of 4608 (H) × 3456 (V), a total of 16 million pixels, and a pixel size of 3.76 μm.The design result show that in the full field of view ,the system's MTF value at 90 lp/mm is greater than 0.3, and in the center field of view the value is greater than 0.7. The size of all field spot’s root-mean-square(RMS) are smaller than the smallest pixel of the detector, the relative illuminance of the system is greater than 50% in the full field of view and all other indicators also meet the requirements.

For the purpose of testing optical path difference of a large optical window, a method of testing a large optical window with a concave spherical mirror is introduced. First, the principle of testing the optical window with a concave spherical mirror was provided; second, the geometrical and wavefront expressions were derived in detail to evaluate the accuracy of testing the large optical window with a concave spherical mirror;third, The accuracy of the method was simulated and analyzed with the derived expressions, the factors of influencing accuracy were gave at the same time. It was shown that the method has a high accuracy when the used concave spherical mirror had a proper relative aperture.

Surface roughness is a key factor to evaluate the machining quality of parts and affect the sealing performance of products, especially for aerospace propulsion valve products with high sealing performance requirements. In this paper, a multi region sampling stitching method and multiple sampling mean methods are proposed to evaluate the surface roughness of small surface structures. And the uncertainty of micro size measurement is systematically analyzed. And three measuring methods on different structural sealing parts are compared and analyzed. The test results show that the roughness measurement method proposed in this paper is accurate and effective. The relative error of this measurement is less than 1%. It meets the high sealing surface quality requirements of aerospace products. This measurement method has important guiding significance and engineering application value for aerospace propulsion products with high sealing requirements.

With the development of infrared imaging technology, especially high resolution imaging instrument for space remote sensing, the requirement of suppressing stray light the optical system is more and more high, thus suppression of stray light of IR detector module as the core device of target detection and imaging is important. The design and processing cold shield is the key of infrared focal plane detector dewar for suppressing stray light, which mainly play a role in suppressing stray light outside of field view and improving background limited detectivity of IR detector. The structure of the cold shield is mainly effect Geometry Composing Function (GCF) of the stray radiation transmission, while Black coatings of cold shield influence bidirectional reflectance distribution function (BRDF) of stray radiation transmission. This paper mainly study suppressing stray light of cold shield with black phosphating process and black nickel plating and point source transmittance (PST) is used as the evaluation index for suppression of stray light, which can be measured accurately. A PST test system in near infrared wave band has been set up for measurement of cold shield’s PST, which coupling infrared light source with light guide tube for greatly improving the uniformity of infrared light source, while the dynamic range of test system decrease slightly. After testing and verification, light source instability is less than 1% , Non uniformity of light source at the exit of the parallel light tube is 7.4%@ 87.5mm×87.5mm.and dynamic range of test system is 0～1.5×10^-5, thus the test facility can satisfy PST test of stray light. The PST curve with angle for one stage cold shield with black phosphating process and black nickel plating are measured and consistent with numerical simulation, which first decrease rapidly with increase of the angle, then slowly vary after 35 angle for the structure of one stage cold shield, the results is useful for optimizing design of infrared detector modules for control of stray light.

The application of dual-field system with simple structure and wide field of view is more and more extensive. A reflective structure system was used to design two optical systems with a large depth of field to achieve the best imaging results for two different fields of view. The main parameters of the system are: the focal length of the lens is 35mm, the diameter of the pupil is 5mm, and the object distance of the dual field of view is 500mm and 800mm, respectively.The number of lenses in the system is only one biconvex single lens, using a combination of axially variable refractive plates. Moving a single lens can achieve focusing, resulting in high imaging quality and overall system structure is simple.

Phase measuring deflectometry (PMD) with structured light projection and phase-shifting technique is a highly accurate optical surface measuring method. For surface shape measurement of transparent planar elements, PMD suffers from parasitic reflection. To avoid the unwanted effect of parasitic reflection, a method based on fringe frequency tuning and Fourier-transform is introduced in this paper. Numerical simulations and experiments are both conducted to evaluate the performance of the proposed method. An optical planar element with a thickness of 24.5mm is measured, and measurement error is within 200nm PV.

Dielectric metasurfaces is a plane optical device to achieve the desired function by modulating amplitude and phase, polarization for the incident light, and its transmission efficiency is higher than other metasurfaces, these advantages lead to dielectric metasurfaces will be used widely in the future. Nevertheless, the majority of metasurfaces are planar singlelayered structure, which limit seriously the view field and effect of monochromatic imaging. Here, we demonstrate a composed dielectric meta-lens doublet by the electromagnetic simulation can achieve perfectly diffraction-limited monochromatic focus for the polarization-insensitive incident lights at a wavelength of 375 nm, which has the view field of 60°, the numerical aperture of 0.5, and a focal length of 380μm. Due to the dielectric meta-lens doublet has the scaling of subwavelength at ultraviolet light, and the devices have high distinguishability, it can be used widely in nanolithography, imaging with large view field, and other optical domains.

Metalenses highlight the potential of planar optics and can respond to the growing demand for miniaturization of conventional imaging lenses in portable and wearable electronic devices, computer vision, and microscopy. This paper characterized a set of mid-wavelength infrared (MWIR) metalenses operating at 4 μm. We derived the radius distribution of the nanopillar at each position based on rigorous coupled-wave analysis, then the metalenses were simulated with focal length f =14 μm and a total of 121 nanopillars by FDTD. Experimental results indicated that the focal spot size of the MWIR metalenses was close to the diffraction limit, and the field of view was as large as 50°. Most importantly, images captured by the MWIR metalenses had a comparable quality to the one by a conventional lens, while metalenses have the advantages of a smaller footprint and negligible weight, making them attractive for further deployment.

The distribution of thermal mismatch strain and radius of curvature of CdTe/Si(211) sample were analyzed by theoretical calculation and laser interferometer measurement at room temperature. The theoretical calculation results showed that the strain profiles and curvature radius of CdTe grew on asymmetry Si(211) surface are asymmetric along in-plane direction along [1-1-1] and [01-1]. The laser interference measurement result of the CdTe/Si(211) sample showed that the tensile strain in CdTe epilayer is smaller than the theoretical calculation. Further study showed that the plastic deformation with positive direction of surface curvature radius was formed during the high temperature deoxidation process of silicon substrate. The plastic deformation of Si substrate reduced the bending degree of CdTe/Si (211) heterostructure, so the thermal mismatch strain was also reduced.

Full-color holographic waveguide display usually consists of over-complex multi-coupling gratings or several-waveguide-combined structure, which results in larger system and higher weight. As to this problem, a full-color holographic waveguide display with monolayer grating and single plate structure is proposed. This configuration consists of two gratings to realize the light input and output, and expansion of the exit pupil. To display the RGB color with a better uniformity in the wide field of view, with the Rigorous Coupled-wave Analysis (RCWA),the shape of grating and grating films are designed and optimized.