Abstract:Through analysis of the current status and future requirement of a panorama system, a new design idea of the panorama system is given. In the system, an optical method is used to combine four optical paths into one optical path and a detector is used to replace several detectors so that its cost and volume are reduced. Since the coherent design is used in both the spectral band of 3μm to 4.3μm and the spectral band of 4.3μm to 5μm, the target dectection and recognition capability of the system is better than that of the monochromatic system under the complicated environment. Its effective reconnaissance probability is improved and its false alarm probability is reduced greatly. Because the 45°×11.25°field of view compressed proportionally from the 360°×90°field of view is used, its imaging quality is fine.

Abstract:To develop an advanced air- and space-based quantitative stereo imaging earth detection system by integrating a Light Detection and Ranging (LIDAR) system with a hyperspectral technology is an urgent need for our country to monitor atmosphere, land and ocean quantitatively. The correlation of the laser with the land, water and atmosphere and its remote response in hyperspectra are the core theoretical basis of the air- and space-based quantitative stereo imaging earth detection system. 　　The current status and development trend of the LIDAR earth detection system are overviewed. A new stereo earth detection system based on a LIDAR system and a hyperspectral remote sensing technology is proposed. Its operation principle and characteristics are presented. The key techniques and research ideas of the system are described in the following five aspects: the generalized atmospheric and topographic radiation correction of LIDAR and hyperspectral images, the generation of the images of aerosol optical path and path radiation, the non-uniform water and underwater topographic correction of LIDAR, the correlation of LIDAR and erspectral signals with media and targets and the multi-source data fusion.

Abstract:There are several kinds of solid state imaing sensors such as visible CCDs, IRCCDs, CMOS and infrared focal plane arrays (IRFPA). Their basic injection mode is that the signal is transported directly from a photodiode to a transition area via an injection channel. The research and development of direct injection techniques over the past 30 years are summarized. The theory and basic formulas of the direct injection mode of visible and infrared imaging sensors are analyzed. The result shows that the increase of the transconductance of an input gate and the impedance of a photodiode is the most effective method to improve injection efficiency when the sampling frequency is low. The transconductance of an input gate can become infinite by using a new current mirroring direct injection circuit when the impedance of a photodiode is low, and hence the injection efficiency can be close to 100%. The new circuit design method is analyzed. A direct injection circuit with a 64-element InSb linear array is developed. The preliminary test indicates that its injection efficiency is close to that of the theoretic analysis.

Abstract:Mechanical polishing can result in mechanical damage at the surface of an InSb wafer to a certain extent, increase the surface roughness of the wafer and affect the performance of the final device. However, chemical polishing can remove the surface scratch of the wafer and decrease the surface roughness. The InSb wafer is polished mechanically and further polished with a low concentration Br2-MeOH solution. The morphology, total thickness variation (TTV), roughness, surface composition and impurity of the polished and unpolished InSb wafers are compared. The result shows that when the InSb wafer is polished with a low concentration Br2-MeOH solution, the erosion rate is stable and can be controlled easily and the surface scratch can be removed effectively and hence a flat mirror-like surface can be obtained. The chemically polished wafer has its surface roughness of 6.443nm, a TTV of 3.4μm and an atomic ratio of In/Sb close to unity. Compared with the traditional CP4-A and CP4-B etching solution, the low concentration Br2-MeOH solution is more suitable for polishing the InSb wafers chemically.

Abstract:In the conventional high-tech war, as a main equipment of each country's troop, the second generation anti-tank missile is a severe threat against a tank. Therefore, it is necessary to develop tank-borne and armored vehicle-borne jammers which can countermeasure the second generation anti-tank missiles effectively. The development status and basic performance of the vehicle-borne infrared jammers at home and abroard are presented. The jamming principle of the vehicle-borne infrared jammer is analyzed and its structure and some key techniques are also discussed.

Abstract:In the pratical use, the output power of an infrared Raman laser will be decreased obviously (up to 50%～70%) after it is used for four or five years. In this paper, it is declared theoretically that the leakage and photolysis reaction of the methane gas used are the the main reasons why the laser output power is decreased. The experiment shows that with the increase of the pressure of the methane gas, the high order Stokes light will be enhanced and the first order Stokes light will be inhibited in the Raman shift. At the same time, the photolysis reaction of the methane gas can result in the precipitation at the Raman window. To solve these problems, it is necessary to improve the sealing performance of the Raman laser and add buffer gas (e.g. H2, He, Ar) in the laser so as to inhibit the photolysis reaction of the methane gas to a certain extent.

Abstract:In recent years, people's demand for wirless wide-band communication is growing stably. Because of the development of microwave wireless network, the bandwidth and frequency of radio wave are improved greatly. However, only wireless optical interconnection can meet the ideal wide-band requirement of data transmission. As the final schemes of many wireless communication systems, wireless optical interconnection techniques are also selected as the long-term solution strategies. Moreover, many advangtages of the wireless optical interconnection have not been fully mined and a lot of basic and application research need to be further carried out at both experimental level and commercial level. At abroad, the wireless optical transmission at Gb/s has been verified in laboratory. However, the indoor wireless optical interconnection system in use only can operate at the speed of 155Mb/s. In this paper, the transceiver, performance and security of the wireless optical interconnection technique are overviewed.

Abstract:A fully automatic lighting control system with a Hall sensor was designed on the basis of the analysis of various kinds of switches. The system controlled the lighting and extinguishing of the lamps through the openning and closing of a door. The lamps were automatically turned on or extinguished whenever the door was opened. When the door was closed, the lamps did nothing. The opening and closing signals of the door were transformed into electric signals by the Hall sensor in the circuit. The electric signals were received by a CD4017 counting and pulse distributor in which the electric signals were transformed into the signals for triggering a two-way thyristor to control the lighting and extinguishing of the lamps. The actual circuit was designed and simulated. The simulation result showed that the system was able to control lamps basically and its energy-saving was remarkable. It was cheap, easy to make and could be widely used in public lavatories for controlling lamps.

Abstract:The design method of a photoinduced plasma Fresnel zone plate antenna is described. A near infrared laser array with its central wavelength of 808 nm is used to illuminate a high resistivity silicon wafer through an optical mask (the negative of a Fresnel zone plate). Then, the illuminated silicon wafer exhibits the diffraction characteristics of the Fresnel zone plate and hence realizes the focusing of the incident millimeter wave. This anntena is verified experimentally at the frequency of 94GHz and its gain is up to 4dB.

Abstract:The normalized noise power spectrum is a function that appears in the definition formula for the signal-to-noise ratio of an infrared imaging system. It is seldom mentioned that how to solve or obtain the detailed expression of this function in references. A practical method for the estimation of normalized noise power spectrum of an infrared imaging system is presented. It is based on numerical approximation and can be implemented with the polynomial fitting function and MATLAB. The method is simple and easy to use.

Abstract:The common image enhancement algorithms are analyzed comparatively according to the characteristics of infrared images. An infrared image enhancement algorithm based on the high frequency emphasis filtering of a Butterworth high pass filter and the histogram equalization is proposed. First, an infrared image is divided into a high frequency part and a low frequency part by using the Butterworth high pass filter. Then, the high frequency part is processed emphatically by using a high frequency emphasis filter. Finally, the histogram of the image is processed in equalization so as to obtain an enhanced image. The experimental results show that in the processed image, the detailed information is apparent and the visual effect is improved. The processing result is satisfied.