Abstract:Field of View (FOV) is one of the important parameters of an infrared optical system. It is inversely proportional to the focal length of the optical system. The FOV can be adjusted by changing the focal length or by zooming. The core of this adjustment is the zoom lens. The FOV concept of an infrared optical system is analyzed in detail. The idea and development trend of infrared zoom technology are presented mainly on the basis of the related papers published domestically.

Abstract:Graphene has the features of high electron mobility, high transmittance (T≈97.7%) and adjustable Fermi energy. The electron mobility of GaAs is 5 to 6 times higher than that of silicon. After introducing indium arsenide quantum dots, the photoelectric detector will has the features of low dark current, high operation temperature, high responsivity and high detectivity. Therefore, it can be used to fabricate fast, high quantum efficiency and wide spectrum photoelectric detectors. The I-V characteristics and photoresponse of a Schottky junction based on a graphene-InAs/GaAs quantum dot hybrid structure are studied. The results show that at the bias voltage of 0 V, the device shows its photoresponse in the wavelength range 400 nm to 950 nm with the peak response of 0.18 A/W. At the reverse bias voltage, its peak response can reach 0.45 A/W. Through the analysis of the temperature dependence of dark current, the barrier height of the Schottky junction at room temperature and 80 K is obtained.

Abstract:To realize high sensitivity ultraviolet (UV) detection, a UV imaging system based on digital Time Delay Integration (TDI) is designed innovatively by using a software windowing technology on the basis of a 600×500 UV Charge Coupled Device (CCD) image sensor. The noise sources of the imaging system and the influence of M-stage digital TDI on the Signal-to-Noise Ratio (SNR) of the imaging system are analyzed in detail. The influence of M-stage digital TDI technology on the SNR of the imaging system is analyzed in theory. Then, the implementation of digital TDI algorithm within FPGA is presented in detail and the interaction process of the data collection system in PC is given. The experimental results show that the UV imaging system based on digital TDI technology can obtain higher image contrast, better SNR and excellent imaging quality.

Abstract:A multi-channel time interval parallel measuring method based on FPGA is designed on the basis of the principle of delay line interpolation. This method can be used to solve the parallel measuring problem of a multi-channel lidar with up to 52 channels. The system in this paper mainly consists of a pulse shaping circuit, a measuring circuit and a data processing module etc. The experimental results show that the average variance of each channel is in the range 59.55 ps to 70.66 ps. The uniformity of each channel's average value is 446.8 ps. The consistency error is small. Because of the advantages of stability, high precision, small volume and easy use, the system can provide technical basis for the wide application of high precision multi-channel information acquisition technology in airborne multi-beam lidars.

Abstract:The causes for nonuniformity of infrared imaging systems are theoretically studied in the following three aspects: the response characteristics of detectors, the relative radiation of optical systems and the stray light from system housings. In an Infrared Focal Plane Array (IRFPA), the difference of structures and materials of detection elements may affect their quantum efficiency and dark current and hence affect their response characteristics. The optical system mainly affects the scene flux distribution through its pupil distortion matrix. The contribution of the radiation from the optical system itself to the nonuniformity can be ignored. The stray light from the housing can be divided into the high temperature part and the low temperature part. By ignoring the low temperature part and introducing the concept of System Cold Shield Efficiency (SCSE), a high temperature component radiation model is established. This theoretical research is of a certain referential value to the design and nonuniformity correction of optical systems.

Abstract:The mid-wavelength infrared radiation characteristics of turbojet engine powered missiles are studied. The calculation models of radiation intensity of exhaust nozzle, exhaust plume and skin of an antiship missile are established respectively. The influence of exhaust plume on nozzle radiation and plume radiation is considered. The attenuation characteristics of infrared radiation in atmosphere in the 3 to 5 μm waveband are analyzed by using the MODRTAN software. Finally, the theoretical calculation result is compared with the experimental result. The results show that the established calculation models and methods can simulate the infrared radiation characteristics of antiship missiles at different detection angles.

Abstract:To meet the need of long range real-time monitoring in the opto-electronic measurement of shooting ranges, the image signals collected by a digital camera usually need to be converted into the video signals of Serial Digital Interface (SDI) and overlapped with the corresponding information for displaying. To solve this problem, a Decklink Duo acquiring card is used to convert the video signals in Camera Link Full mode into the dual channel SDI output signals by means of Microsoft Visual Stdio 2010 and OpenCV2.4.11. Then, the output signals are processed by character information overlapping and infrared pseudo-color simulation. In the experiment, the expected displaying effectiveness is achieved. It shows that this method is effective and can meet the requirements of practical tasks.

Abstract:The total thermal resistance of a straight heat pipe heat transfer system at room temperature is studied experimentally. The total thermal resistance of the heap pipe and the resistances of heat pipe and heat-end and cold-end mounting surfaces when the system is installed with different torques are analyzed mainly. The research result shows that test environment has a certain influence on the heat transfer capability of the system. The thermal resistances of the heat-end and cold-end mounting surfaces are greater in vacuum than those in atmosphere. The mounting torque of the screw used may affect the thermal resistances of contact surfaces. In both environments, the thermal resistance of the cold-end mounting surface with a torque of 0.4 Nm is about 2.4 times greater than that of it with a torque of 1.2 Nm under a certain heat load.