Abstract:Polarization sensitivity is one of the main performance characterization indexes for advanced remote sensing instruments. It is very important in the quantification of high-precision remote sensing information extraction. Optical film is a very important means for controlling the polarization sensitivity of remote sensing instruments. On the basis of the theory of transfer matrix of optical films, the design, analysis and development of several types of optical films including metal reflective film, dielectric-metal-dielectric edge filtering film, dielectric edge filtering film, antireflection coating and band-pass filtering film are carried out according to the control requirements of polarization sensitivity. The measured results of polarization sensitivity of some coated optics and the actually controlled polarization sensitivity of the remote sensing instrument systems using those coated optics are given.

Abstract:Taking Cu(NO₃)₂·3H₂O, Cr(NO₃)₃·9H₂O, Bi(NO₃)₃·3H₂O and ethylene glycol as raw materials, Cu₂Bi₂Cr₂O₈ thin films were fabricated on SiO₂ substrates by a sol-gel process. The thin film samples were characterized by X-ray Diffraction (XRD) patterns and Raman tests. The results showed that the Cu₂Bi₂Cr₂O₈ thin films had good optical properties. Their band gap was 1.49 eV. In the magnetic hysteresis (M-H) loop measurements, the Cu₂Bi₂Cr₂O₈ thin films showed their excellent ferromagnetism.

Abstract:The structure of a n-on-p Hg1-xCdxTe infrared detector is modeled by the Sentaurus TCAD software. The influence of junction depth on the current of a photovoltaic diode is simulated and analyzed. The results show that the influence of junction depth on the current of the diode is affected by the thickness of absorption layer and the carrier concentration in p region. The change of the diodes for different wavelengths with junction depth is fitted and the junction depth for maximal current at different wavelengths is obtained.

Abstract:A system containing an optical platform and a galvanometer is set up for InSb detector chips on the basis of an ultraviolet picosecond laser. By fixing the laser pulse repetition frequency, different technological conditions such as low-energy multi-knife- number and high-energy less-knife-number are discussed and the technological conditions suitable for laser scribing of InSb detector chips are obtained. The results show that by using these technological conditions, both heat effect and edge breakage meet the requirements of the project.

Abstract:Non-Line-of-Sight (NLOS) imaging can be used to detect and image hidden objects around the corner, behind smoke and so on. It is of important value to many research fields like machine vision, public security, medical imaging, disaster relief and autonomous vehicles. This technology utilizes a pulsed laser and a time-resolved detector to scan and detect a certain surface. At present, NLOS imaging still has some shortcomings such as time-consuming in scanning and computer-reconstruction. To overcome these shortcomings, a rapid staring detection and reconstruction method is proposed. The simulation results show that it can be used to detect highly-scattered objects and widen the field of view effectively.

Abstract:Normal incidence cannot fully reflect the working condition of diffractive optical elements (DOEs) for imaging. However, oblique incidence can reflect their general working condition. The relationship between the diffraction efficiency and the incident angle is established for triple-layer diffractive optical elements (TLDOEs). For the three influencing factors, such as the determination of incident direction, the selection of the substrate materials on both sides and the selection of medium materials, the relationship between the diffraction efficiency and the incident angle is simulated and analyzed for TLDOEs. The results show that the diffraction efficiency decreases slowly with the increase of incident angle when the light is incident from the positive harmonic diffractive element (HDE). The larger of the difference of abbe number for the substrate materials of TLDOEs is, the more slowly of the corresponding diffraction efficiency decreases with the increase of incident angle. The selection of the medium material is decided by the incidence angle range of TLDOEs. The analysis method and conclusions are applicable to the visible or infrared TLDOEs.

Abstract:Flat panel Liquid Crystal Displays (LCDs), especially TFT-LCDs have excellent performance, good mass production characteristics, high degree of automation, low cost of raw materials and broad development space. The cutting step plays a pivotal role in the fabrication process of LCDs. The main function of cutting is to process large substrate products. According to the designed cell size, a large substrate is divided into several small cells. The control of the parameters and operation skills in processing has important impact on the strength and function of LCDs. With the development of LCD equipment towards large size, ultra-thin and pixel densification, the requirements of product reliability are becoming higher and higher. How to reduce the impact of cutting on LCD yield and reliability is the focus of this paper.

Abstract:Nowadays, the artificial imitations of obsidian in jewelry markets are very similar to the natural obsidian in appearance, basic properties and substance composition. This may confuse the consumers and challenge the routine testing. Taking the natural and artificial obsidian as the objects of study, a method which combines the infrared reflectance spectroscopy with the transmission spectroscopy is used to analyze the difference between the natural obsidian and its artificial imitations. The results show that both of them are amorphous SiO2 substances, i.e. vitreous substances. Due to their different formation processes and medium environment, they have different degree of spectral division in the infrared spectral fingerprint region from 600 cm-1 to 1400 cm-1. In the characteristic frequency region from 2600 cm-1 to 3700 cm-1, the position and strength of their H2O and O-H vibration absorption bands are also different. The results provide a new technical idea for the rapid, accurate and nondestructive identification of obsidian.