This PDF file contains the front matter associated with SPIE Proceedings Volume 10459 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

By utilizing terahertz time-domain spectroscopy and fourier-transform infrared spectroscopy, several kinds of traditional Chinese pigments have been investigated covering the spectral region 0.25 THz- 7 THz. The experimental results demonstrate that all pigments studied in the present work show a series of characteristic absorption spectra, which are unique to the pigment species. According to the fingerprint spectra, we can confirm that the traditional Chinese pigments have been applied to the heritage buildings and artworks. Compared with X-ray diffraction, Raman spectroscopy and near-infrared spectroscopic techniques, these experimental results reveal that terahertz time-domain spectroscopy could further fill their physical information what other techniques cannot obtain.

An effective approach for reconstructing on-axis lensless Fourier Transform digital hologram by using the screen division method is proposed. Firstly, the on-axis Fourier Transform digital hologram is divided into sub-holograms. Then the reconstruction result of every sub-hologram is obtained according to the position of corresponding sub-hologram in the hologram reconstruction plane with Fourier transform operation. Finally, the reconstruction image of on-axis Fourier Transform digital hologram can be acquired by the superposition of the reconstruction result of sub-holograms. Compared with the traditional reconstruction method with the phase shifting technology, in which multiple digital holograms are required to record for obtaining the reconstruction image, this method can obtain the reconstruction image with only one digital hologram and therefore greatly simplify the recording and reconstruction process of on-axis lensless Fourier Transform digital holography. The effectiveness of the proposed method is well proved with the experimental results and it will have potential application foreground in the holographic measurement and display field.

In this paper, a bending sensor based on microstructured fiber is proposed. The fiber sensor is in-line, all-fiber and distributed sensing. Especially, by contrast to the bending sensors which based on multicore microstructured fiber, it is immune to the bending directions and has good repetition along different directions. Thus it is convenient to be buried into the materials or structures without considering the radial orientation. The sensor is suitable for practical application and to monitor the bending radius of the structure. The other potential application of the sensor is that it may transport the healing materials in its hollow core.

Light-field cameras are used in consumer and industrial applications. An array of micro-lenses captures enough information that one can refocus images after acquisition, as well as shift one’s viewpoint within the sub-apertures of the main lens, effectively obtaining multiple views. Thus, depth estimation from both defocus and correspondence are now available in a single capture. And Lytro.Inc also provides a depth estimation from a single-shot capture with light field camera, like Lytro Illum. This Lytro depth estimation containing many correct depth information can be used for higher quality estimation. In this paper, we present a novel simple and principled algorithm that computes dense depth estimation by combining defocus, correspondence and Lytro depth estimations. We analyze 2D epipolar image (EPI) to get defocus and correspondence depth maps. Defocus depth is obtained by computing the spatial gradient after angular integration and correspondence depth by computing the angular variance from EPIs. Lytro depth can be extracted from Lyrto Illum with software. We then show how to combine the three cues into a high quality depth map. Our method for depth estimation is suitable for computer vision applications such as matting, full control of depth-of-field, and surface reconstruction, as well as light filed display

Producing of conventional optical reflection hologram can be classified into one-step method and two-step method. In one-step method, only the diverging light of the object could be recorded, and the reconstructed scene is a virtual one behind the recording medium. In two-step method, the diverging light or the converging light could be recorded alternatively. However, the process is complicated considering double exposures. We propose a novel method of one-step reflection hologram. The object is first imaged by a 4f optical system, then the interference fringes are recorded by single exposure. The reconstructed image can be either a virtual image behind the recording medium, or a real image in front of the recording medium. The ideal imaging properties of 4f optical system have been demonstrated theoretically and the proposed method has been verified experimentally.

A spatial frequency index method is proposed to cull the occlusion in computer generated hologram. The object points with the same spatial frequency are put into a set, and only the point closest to the hologram is contributed to the hologram because of their mutual occlusion. The phases of corresponded spatial frequency are precomputed and stored in a table. The phases on the hologram are obtained from the table according to the spatial frequency of object point. Experiments are performed and the results demonstrate that the proposed method can cull the hidden surfaces of 3-D scene correctly. The occlusion effect can be well reproduced along with the speeding up of the calculation.

Interferometry is a high-precision method to test the transmitted wavefront error of lens. However, the radiuses of curvature of some part of lens are too small to produce interference with other optical surface. The resulting interference ring is parasitic in the measured wavefront. The influence of the phase and position of parasitic interference ring on the measured wavefront are analyzed in this paper. Analysis results shows that the existence of parasitic interference ring seriously affects the three-dimensional shape of the measured wavefront. To reduce its influence, a new wavelet filtering method is demonstrated and discussed. By subtract the wavelet decomposition vector of quadratic sum of XY direction gradient from the wavelet coefficients of the measured wavefront, the wavelet reconstruction decomposition vector of the real wavefront are obtained. The whole process is described in detail, and the simulation experiments are done. Compared with the median filtering and mean filtering, the result of the wavelet filtering based on the gradient wavefont is closer to the truth wavefront. This method effectively improves the wavefront filtering effect when the parasitic interference ring exists, and advantageous to guide higher quality lens processing.

Virtual Reality (VR) products serve for human eyes ultimately, and the optical properties of VR optical systems must be consistent with the characteristic of human eyes. The monocular coaxial VR optical system is simulated in ZEMAX. A diffraction grating is added to the optical surface next to the eye, and the lights emitted from the diffraction grating are deflected, which can forming an asymmetrical field of view(FOV). Then the lateral chromatic aberration caused by the diffraction grating was corrected by the chromatic dispersion of the prism. Finally, the aspheric surface was added to further optimum design. During the optical design of the system, how to balance the dispersion of the diffraction grating and the prism is the main problem. The balance was achieved by adjusting the parameters of the grating and the prism constantly, and then using aspheric surfaces finally. In order to make the asymmetric FOV of the system consistent with the angle of the visual axis, and to ensure the stereo vision area clear, the smaller half FOV of monocular system is required to reach 30°. Eventually, a system with asymmetrical FOV of 30°+40° was designed. In addition, the aberration curve of the system was analyzed by ZEMAX, and the binocular FOV was calculated according to the principle of binocular overlap. The results show that the asymmetry of FOV of VR monocular optical system can fit to human eyes and the imaging quality match for the human visual characteristics. At the same time, the diffraction grating increases binocular FOV, which decreases the requirement for the design FOV of monocular system.

Pulse Coupled Neural Network (PCNN) is improved by Adaptive Lateral Inhibition (ALI), while a method of infrared (IR) dim small target segmentation based on ALI-PCNN model is proposed in this paper. Firstly, the feeding input signal is modulated by lateral inhibition network to suppress background. Then, the linking input is modulated by ALI, and linking weight matrix is generated adaptively by calculating ALI coefficient of each pixel. Finally, the binary image is generated through the nonlinear modulation and the pulse generator in PCNN. The experimental results show that the segmentation effect as well as the values of contrast across region and uniformity across region of the proposed method are better than the OTSU method, maximum entropy method, the methods based on conventional PCNN and visual attention, and the proposed method has excellent performance in extracting IR dim small target from complex background.

Based on concept of eye space, we proposed an idea to achieve multi-view autostereoscopic display with densest viewpoints (for largest tolerance) which reaches physical limitation of density. The physical limitation of separation between two neighboring view-points is one eye spacing for largest tolerance in binocular view based display; the display can be achieved by using light-shutter-screen with fast-enough-switching and a circuit hardware called address driving matrix. The idea is applied for both binocular view based and depth map based display. For the former (binocular view), one shutter screen is placed at front of 2D-display screen with address driving matrix and two video streams of left and right eyes; for the latter (not binocular view, a kind of quasi-holography display), two shutter screens are placed at front of 2D-display screen with one 2D video stream and one depth map (depth map can be generated from two video streams of left and right eye or be obtained from a depth camera), in this case, each of all screens (besides each of shutter screens, 2D-display screen also) need separate address driving matrix, and the physical limitation of separation of view-points is further reduced to half of eye spacing for largest tolerance. Current technologies are ready for building the address driving matrix, but not ready yet for the fast- enough-switching, for example, current LCD is not fast enough for this purpose. Therefore, this will bring many challenges and new opportunities for those physicist and engineers who work in area of fast light switch (not only limited in LCD), besides in autostereoscopic display.

According to nonimaging optical principle and traditional LED free-form surface lens, a new kind of LED free-form tilted lens was designed. And a method of rapid modeling based on Scheme language was proposed. The mesh division method was applied to obtain the corresponding surface configuration according to the character of the light source and the desired energy distribution on the illumination plane. Then 3D modeling software and the Scheme language programming are used to generate lens model respectively. With the help of optical simulation software, a light source with the size of 1mm*1mm*1mm in volume is used in experiment, and the lateral migration distance of illumination area is 0.5m, in which total one million rays are computed. We could acquire the simulated results of both models. The simulated output result shows that the Scheme language can prevent the model deformation problems caused by the process of the model transfer, and the degree of illumination uniformity is reached to 82%, and the offset angle is 26°. Also, the efficiency of modeling process is greatly increased by using Scheme language.

Artificial metamaterials with appropriate design can exhibit unique electromagnetic phenomena which do not exist in natural materials. Some studies have shown that the method of breaking the geometric symmetry is capable to modify the electromagnetic responses. Here, we simulated and measured the transmission spectra of period arrays of subwavelength double-bar structure. The obtained results show the trapped-mode resonance with Fano-shaped spectrum can be induced in terahertz metamaterial with asymmetric double-bar structure, accompanied with a metamaterial induced transparency window between two resonant dips. And the bar spacing and lattice constant have great impact on the coupling strength concerned with the transparency position and spectral lineshape. We attribute there are two mechanisms together determine the coupling pattern between the bar array and the terahetz wave, the coupling between the bars of the same unit cell and the coupling between the bars of the neighbouring cells. Our obtained results indicate that such metamaterial with very simple configuration could also provide the potential application in the field of terahertz slow-light devices, amplitude and phase modulators.

In the pulsed fiber amplifiers with repetition frequency of several tens kHz, amplified spontaneous emission (ASE) is easy to build up because of the low repetition frequency and weak pulse signal. The ASE rises the difficulty to amplify the weak pulse signal effectively. We have demonstrated an all-fiber preamplifier stage structure to amplify a 40 kHz, 10 ns bandwidth (FWHM) weak pulse signal (299 μW) with center wavelength of 1062 nm. Compared synchronous pulse pump with continuous wave(CW) pump, the results indicate that synchronous pulse pump shows the better capability of increasing the output power than CW pump. In the condition of the same pump power, the output power of synchronous pulse pump is twice as high as CW pump. In order to suppress ASE, a longer gain fiber is utilized to reabsorb the ASE in which the wavelength is shorter than 1062nm. We amplified weak pulse signal via 0.8 m and 2.1 m gain fiber in synchronous pulse pump experiments respectively, and more ASE in the output spectra are observed in the 0.8 m gain fiber system. Due to the weaker ASE and consequent capability of higher pump power, the 2.1 m gain fiber is capable to achieve higher output power than shorter fiber. The output power of 2.1 m gain fiber case is limited by pump power.

There are many disadvantages such as lower timeliness, greater manual intervention in multi-channel projection system, in order to solve the above problems, this paper proposes a multi-projector correction technology based on color coding grid array. Firstly, a color structured light stripe is generated by using the De Bruijn sequences, then meshing the feature information of the color structured light stripe image. We put the meshing colored grid intersection as the center of the circle, and build a white solid circle as the feature sample set of projected images. It makes the constructed feature sample set not only has the perceptual localization, but also has good noise immunity. Secondly, we establish the subpixel geometric mapping relationship between the projection screen and the individual projectors by using the structure of light encoding and decoding based on the color array, and the geometrical mapping relation is used to solve the homography matrix of each projector. Lastly the brightness inconsistency of the multi-channel projection overlap area is seriously interfered, it leads to the corrected image doesn’t fit well with the observer's visual needs, and we obtain the projection display image of visual consistency by using the luminance fusion correction algorithm. The experimental results show that this method not only effectively solved the problem of distortion of multi-projection screen and the issue of luminance interference in overlapping region, but also improved the calibration efficient of multi-channel projective system and reduced the maintenance cost of intelligent multi-projection system.

A lenticular-type super multi-view (SMV) display method with narrow structure pitch and small light intensity ripple is presented. Normally, increasing the number of viewing zones can reduce the amplitude of the light intensity ripple. The viewing zones’ number is proportional to the structure pitch of the lenticular lens array. However, wide structure pitch will decrease the spatial display resolution. Here, a lenticular lens array with one pitch covering 2.2 sub-pixels and novel arrangement of left and right sub-pixels groups are designed. The proposed display method can provide twenty-two viewing zones. By the introduction of tracking device, both binocular parallax and motion parallax are experienced. By measuring with the photometer, the light intensity ripple is 0.7%, which is far smaller than the traditional SMV display with 8 viewing zones. As the fluctuation of light intensity is reduced, the 3D perception effect is improved.

Asymmetric split-ring resonators (SRRs) exhibit different resonant modes and phenomena that do not have in symmetric structure, such as Fano resonance, electromagnetic induced transparency, and plasma resonance hybridization. The asymmetric SRR was first confirmed to produce narrow linewidth resonance and has a high quality factor. Then it extends to the terahertz and near infrared bands. It has been found that the most common way to modulate the electromagnetic response characteristics is to change the asymmetry of the SRR and the coupling strength between the resonators. Here we use the finite-difference time-domain (FDTD) method to simulate the electromagnetic response characteristics of asymmetric structures. When the polarization direction along the bottom bar of the U-shaped structure, there are two similar resonance dips like those in typical SRR structure. When the incident wave is perpendicular to the bottom bar, there is only one dipole resonance. However, with the broken of the symmetry, the resonant behaviors will change. In horizontal direction, both the resonant frequency and transmittance has changed. In the vertical polarization, there are three resonant dips in transmission spectrum. Meanwhile a sharp window appears in transmission spectrum. In addition, when we turn the bottom bar of the U-shaped structure into the arc shape, we just find very slight change in frequency-shift and modulation depth in both cases, showing the impact of the short arc is nearly equivalent to the linear dipole resonance. Our obtained results indicate that we could tune the electromagnetic resonances in metamaterials and the interaction mechanism with terahertz wave.

The double-liquid focus-tunable lens based on electrowetting on dielectrics is attracting many researchers’ attention because of compact volume, quick responding speed, low consumption etc. In this paper, a focus-tunable liquid cylindrical lens based on electrowetting is designed, the structure and operating principles of this lens are introduced. COMSOL Multiphysics is chamber, and the focal length is varied continuously. According to the materials used in our laboratory, the focal length is estimated, ranging between (-∞, -38.6mm)υ(61.4mm, +∞).

Panoramic imaging has been closely watched as one of the major technologies of AR and VR. Mainstream panoramic imaging techniques lenses include fish-eye lenses, image splicing, and catadioptric imaging system. Meanwhile, fish-eyes are widely used in the big picture video surveillance. The advantage of fish-eye lenses is that they are easy to operate and cost less, but how to solve the image distortion of fish-eye lenses has always been a very important topic. In this paper, the image calibration algorithm of fish-eye lens is studied by comparing the method of interpolation, bilinear interpolation and double three interpolation, which are used to optimize the images.

In the information age, the rapid development in the direction of intelligent video processing, complex algorithm proposed the powerful challenge on the performance of the processor. In this article, through the FPGA + TMS320C6678 frame structure, the image to fog, merge into an organic whole, to stabilize the image enhancement, its good real-time, superior performance, break through the traditional function of video processing system is simple, the product defects such as single, solved the video application in security monitoring, video, etc. Can give full play to the video monitoring effectiveness, improve enterprise economic benefits.

Three-dimensional (3D) display technologies make great progress in recent years, and lenticular array based 3D display is a relatively mature technology, which most likely to commercial. In naked-eye-3D display, the screen size is one of the most important factors that affect the viewing experience. In order to construct a large-size naked-eye-3D display system, the LED display is used. However, the pixel misalignment is an inherent defect of the LED screen, which will influences the rendering quality. To address this issue, an efficient image synthesis algorithm is proposed. The Texture-Plus-Depth(T+D) format is chosen for the display content, and the modified Depth Image Based Rendering (DIBR) method is proposed to synthesize new views. In order to achieve realtime, the whole algorithm is implemented on GPU. With the state-of-the-art hardware and the efficient algorithm, a naked-eye-3D display system with a LED screen size of 6m × 1.8m is achieved. Experiment shows that the algorithm can process the 43-view 3D video with 4K × 2K resolution in real time on GPU, and vivid 3D experience is perceived.

Sand table technology has a great prospect in wide fields. However, sand table technology is mainly based on two-dimension (2D) display. Based on 3D display and head-tracking technique, a novel 3D sand table technology is proposed. The technology consists of a 3D display module, a head-tracking module and an image processing module. The head-tracking module can track the position of observer's head closing to the center of eyes. According to the position, the image processing module would modify the projection matrix of virtual cameras. 3D virtual scene rendered by the image processing module would be display as if floating upon the projection screen in the display module. An experimental system for the 3D sand table was demonstrated, which offers the observer great field of view (FOV) to watch immersive 3D virtual scene.

A markerless client-server augmented reality system is presented. In this research, the more extensive and mature virtual reality head-mounted display is adopted to assist the implementation of augmented reality. The viewer is provided an image in front of their eyes with the head-mounted display. The front-facing camera is used to capture video signals into the workstation. The generated virtual scene is merged with the outside world information received from the camera. The integrated video is sent to the helmet display system. The distinguishing feature and novelty is to realize the augmented reality with natural features instead of marker, which address the limitations of the marker, such as only black and white, the inapplicability of different environment conditions, and particularly cannot work when the marker is partially blocked. Further, 3D stereoscopic perception of virtual animation model is achieved. The high-speed and stable socket native communication method is adopted for transmission of the key video stream data, which can reduce the calculation burden of the system.

Recently holographic display has attracted much attention for its ability to generate real-time 3D reconstructed image. CGH provides an effective way to produce hologram, and spacial light modulator (SLM) is used to reconstruct the image. However the reconstructing system is usually very heavy and complex, and the view-angle is limited by the pixel size and spatial bandwidth product (SBP) of the SLM. In this paper a light portable holographic display system is proposed by integrating the optical elements and host computer units.Which significantly reduces the space taken in horizontal direction. CGH is produced based on the Fresnel diffraction and point source method. To reduce the memory usage and image distortion, we use an optimized accurate compressed look up table method (AC-LUT) to compute the hologram. In the system, six SLMs are concatenated to a curved plane, each one loading the phase-only hologram in a different angle of the object, the horizontal view-angle of the reconstructed image can be expanded to about 21.8°.

A multi-view autostereoscopic three-dimensional (3D) system is built by using a 2D display screen and a customized parallax-barrier shutter (PBS) screen. The shutter screen is controlled dynamically by address driving matrix circuit and it is placed in front of the display screen at a certain location. The system could achieve densest viewpoints due to its specially optical and geometric design which is based on concept of “eye space”. The resolution of 3D imaging is not reduced compared to 2D mode by using limited time division multiplexing technology. The diffraction effects may play an important role in 3D display imaging quality, especially when applied to small screen, such as iPhone screen etc. For small screen, diffraction effects may contribute crosstalk between binocular views, image brightness uniformity etc. Therefore, diffraction effects are analyzed and considered in a one-dimensional shutter screen model of the 3D display, in which the numerical simulation of light from display pixels on display screen through parallax barrier slits to each viewing zone in eye space, is performed. The simulation results provide guidance for criteria screen size over which the impact of diffraction effects are ignorable, and below which diffraction effects must be taken into account. Finally, the simulation results are compared to the corresponding experimental measurements and observation with discussion.

A method to realize arbitrary views for the lenticular lens array based on autostereoscopic three-dimensional display system is demonstrated. Normally, the number of views is proportional to pitch of the lenticular lens array. Increasing the number of views will result in reducing resolution and enhancing of granular sensation. 32 dense views can be achieved with one lenticular lens pitch covering 5.333 sub-pixels, which does significantly increases the number of views without affecting the resolution. But the structure of pitch and the number of views are fixed. Here, the 3D display method that the number of views can be changed artificially for most structures of lenticular lens is presented. Compared with the previous 32 views display method, the smoothness of motion parallex and the display depth of field are significantly improved.

An improved method for Augmented Reality (AR) glass-free three-dimensional (3D) display based on stereo camera used for presenting parallax contents from different angle with lenticular lens array is proposed. Compared with the previous implementation method of AR techniques based on two-dimensional (2D) panel display with only one viewpoint, the proposed method can realize glass-free 3D display of virtual objects and real scene with 32 virtual viewpoints. Accordingly, viewers can get abundant 3D stereo information from different viewing angles based on binocular parallax. Experimental results show that this improved method based on stereo camera can realize AR glass-free 3D display, and both of virtual objects and real scene have realistic and obvious stereo performance.

Light Guide Plate (LGP) plays an irreplaceable role in Liquid Crystal Display (LCD) backlight. LGP with quantum-dot (QD) shows promise in the development of next-generation displays because of QDs’ beneficial characteristics. In this paper, we present a novel QD LGP for LCD backlight based on QD scattering microstructure array (SMA), in which the QD net dots are located discretely and arranged in arrays on the bottom surface of LGP. The paper first introduces the QD backlight briefly, then discusses the preparation and fabrication process of the proposed prototype, and finally presents a systematic photometric approach to reveal the remarkable advantages of QD backlight. The white-balance is achieved by adjusting the proportion of the QDs in the mixture and optimizing the R-QD / G-QD ratio. The apparent morphology of QD SMA is characterized by OLYMPUS laser microscope, while the optical properties of QD backlight are investigated by F-4600 fluorescence spectrophotometer and SRC-200M spectrum color luminance meter, respectively. Experimental results show that the white balance can be achieved when the QDs account for a certain proportion about 7% within the mixture, and the ratio of R-QD / G-QD is optimized to about 1:12. The proposed system offers an alternative and feasible method for fabricating QD backlight, which may have great application prospects in the future.

In this paper, a performance test system is designed, which is used to produce the difference in temperature between the target and the background, and simulate the infinite infrared targets. The medium-wave imaging system detects infrared target and generates target image. The evaluation of the performance of the medium-wave imaging system is completed by using the standard test method and data processing and analysis of images in the laboratory. The test system, which has the field of view of 30°×30°, the focal length of 34mm, and the distortion is less than 3%, could meet the need of testing the temperature sensitivity, resolution and transfer function of the medium-wave imaging system which the field of view is more than 90°.

Illumination design used to redistribute the spatial energy distribution of light source is a key technique in lighting applications. However, there is still no effective illumination design method for the removing of the chromatic dispersion. What we present here is an achromatic lens design to enhance the efficiency and uniform illumination of white light-emitting diode (LED) with diffractive optical element (DOE). We employ the chromatic aberration value (deg) to measure the degree of chromatic dispersion in illumination systems. Monte Carlo ray tracing simulation results indicate that the chromatic dispersion of the modified achromatic collimator significantly decreases from 0.5 to 0.1 with LED chip size of 1.0mm×1.0mm and simulation efficiency of 90.73%, compared with the traditional collimator. Moreover, with different corrected wavelengths we compared different chromatic aberration values that followed with the changing pupil percent. The achromatic collimator provided an effective way to achieve white LED with low chromatic dispersion at high efficiency and uniform illumination.

In order to meet the needs of engineering applications for high dynamic range CMOS camera under the rolling shutter mode, a complete imaging system is designed based on the CMOS imaging sensor NSC1105. The paper decides CMOS+ADC+FPGA+Camera Link as processing architecture and introduces the design and implementation of the hardware system. As for camera software system, which consists of CMOS timing drive module, image acquisition module and transmission control module, the paper designs in Verilog language and drives it to work properly based on Xilinx FPGA. The ISE 14.6 emulator ISim is used in the simulation of signals. The imaging experimental results show that the system exhibits a 1280*1024 pixel resolution, has a frame frequency of 25 fps and a dynamic range more than 120dB. The imaging quality of the system satisfies the requirement of the index.

This study proposes a method to create a dynamic color hologram by using the coding method. According to the colorimetric principle, a color object can be resolved into three primary color objects. Thus, when we create a dynamic color hologram, we can regard every object as three primary color objects once we obtain the color and three-dimensional coordinate data of the objects. Coordinate data concerning the behavior of the three primary color objects are coded by the relationship between the objects and their hologram images. Therefore, when the three monochromatic holograms are calculated on a plane, they reappear due to conjugate light, and overlap at points in the plane where the color object had been located. Three line-monochromatic Fresnel holograms with stereoscopic image pairs are then computed according to the theory of light propagation and the relationship between object and image. The overlapping images experience interference due to the reference light to form a dynamic color hologram. Experiments showed that the proposed method can simplify the creation of high-quality dynamic color histograms.

In this paper, the Olympic rings pattern is generated by using freeform lens array and illumination light source array. Based on nonimaging optics, the freeform lens array is designed for point light source, which can generate the focused pattern of annular light spot. In order to obtain the Olympic logo pattern of five rings, the array with five freeform lenses is used. By adjusting the emission angle of each light source, the annular spot is obtained at different positions of the target plane and the Olympic rings logo is formed. We used the shading plate on the surface of the freeform lens to reduce the local light intensity so that the light spot overall irradiance distribution is more uniform. We designed a freeform lens with aperture of 26.2mm, focal length of 2000mm and the diameter of a single annual spot is 400mm. We modeled freeform lens and simulated by optical software TracePro. The ray tracing results show that the Olympic rings with uniform illumination can be obtained on the target plane with the optical efficiency up to 85.7%. At the same time, this paper also studies the effects of the target plane defocusing on the spot pattern. Simulations show that when the distance of the receiving surface to the focal plane varies within 300mm, a reasonable uniform and small distorted light spot pattern can be obtained. Compared with the traditional projection method, our method of design has the advantages of high optical efficiency, low cost and the pattern is clear and uniform.

Recently new trend applying wide angle in mobile imaging lens is attracting. Specially, customer requirements for capturing wider scene result that a field of view of lens be wider than 100deg. Introduction of retro-focus type lens in mobile imaging lens is required. However, imaging lens in mobile phone always face to many constraints such as lower total length, low F/# and higher performance. The sensitivity for fabrication may become more severe because of wide angle FOV. In this paper, we investigate an optical lens design satisfy all requirements for mobile imaging lens. In order to accomplish Low cost and small depth of optical system, we used plastic materials for all element and the productivity is considered for realization. The lateral color is minimized less than 2 pixels and optical distortion is less than 5%. Also, we divided optical system into 2 part for robust design. The compensation between 2 groups can help us to increase yield in practice. The 2 group alignment for high yield may be a promising solution for wide angle lens.

In order to meet the needs of engineering applications for low noise imaging system under the mode of global shutter, a complete imaging system is designed based on the SCMOS (Scientific CMOS) image sensor CIS2521F. The paper introduces hardware circuit and software system design. Based on the analysis of key indexes and technologies about the imaging system, the paper makes chips selection and decides SCMOS + FPGA+ DDRII+ Camera Link as processing architecture. Then it introduces the entire system workflow and power supply and distribution unit design. As for the software system, which consists of the SCMOS control module, image acquisition module, data cache control module and transmission control module, the paper designs in Verilog language and drives it to work properly based on Xilinx FPGA. The imaging experimental results show that the imaging system exhibits a 2560*2160 pixel resolution, has a maximum frame frequency of 50 fps. The imaging quality of the system satisfies the requirement of the index.

Silicon-based OLED (Organic Light Emitting Display) microdisplay technology begins to attract people's attention in the emerging VR and AR devices. The high display frame refresh rate is an important solution to alleviate the dizziness in VR applications. Traditional display circuit drivers use the analog method or the digital PWM method that follow the serial scan order from the first pixel to the last pixel by using the shift registers. This paper proposes a novel atomized scan strategy based on the digital fractal scan strategy using the pseudo-random scan order. It can be used to realize the high frame refresh rate with the moderate pixel clock frequency in the high definition OLED microdisplay. The linearity of the gray level is also improved compared with the Z fractal scan strategy.