Study On The Characteristics Of Laser Interference Infrared/television Imaging System

In recent years,as a high-energy weapon,laser weapons have tremendous power.In the modern battlefield,reliable detection and identification,accurate strikes,and the reservation of one's own strength,playing an important role in the optoelectronic confrontation.However,due to the continuous deterioration of the optical environment in the battlefield,the performance of the photovoltaic system is degraded and even destructed.Therefore,it is very urgent to study the characteristics of laser interference infrared/television imaging system.It can improve the adaptability of China's optoelectronic imaging system for the battlefield environment,and has important theoretical and practical value for the protection and construction of the photoelectric investigation system.This article aims at the characteristics of laser interference infrared/television imaging systems.Based on the performance of the system before and after laser interference and on the condition of the on-axis and off-axis,the key issues such as the change of light intensity received by the infrared imaging system and the evaluation of the effect of the laser interference on photoelectric imaging system were studied.The main work are as follows: 1.The transmission characteristics of the paraxial laser through the optical system are introduced,and the ABCD matrix method is used to calculate the geometrical size and power density distribution of the laser spot on each lens surface of the system.Then,based on the generalized Huygens-Fresnel diffraction integral formula,the analytical integral of complex optical system with hard edge apertures is got,which is compared with the numerical integration of the complex Gaussian function expansion method.Finally,for the off-axis Gaussian beam,the control variable method is used to analyze laser beam transmitting different distances,and then the optical intensity changes after passing through the aperture,the optical lens system,and the beam with different incident angles are simulated for the same transmission distance.2.Used to the Debye-Wolf vector diffraction integral formula,the expression of the intensity of deep focusing of a vector beam through a large aperture lens is derived.Firstly,based on the wide-field imaging method of optical imaging,the tilt incident Gaussian beam propagation through lens system is analyzed,the equivalent vector point spread function of direct oblique plane imaging is obtained,and the two-dimensional point spread function of oblique plane imaging at any angle is got.Then,the corresponding point spread function is studied for the x-axis polarization vector Gaussian beam with different incident angles.Finally,the x-axis polarized tilt incident Laguerre Gaussian beam propagation through lens system was studied.The lateral resolution of the three-dimensional point spread function was studied by using the equivalent vector point spread function of direct oblique plane imaging.The simulation of the oblique plane imaging with different incident angles and the light intensity distribution characteristics of different topological charges are performed.3.The damage of CCD of infrared detector by laser,the soft damage of infrared imaging system by laser are analyzed.The laser-irradiated image was analyzed by the blade method,by edge detection and Hough transform to obtain a straight line boundary.According to the speckle distribution after laser interference,Fermi function or Gaussian multi-peak fitting is performed to obtain the edge spread function;the line spread function is obtained by differentiation;then the modulation transfer function is obtained by Fourier transform.A comparative analysis of the modulation transfer function before and after interference was performed.Then,the influence of lasers on detector with different materials,the effect of laser interference on the noise equivalent temperature difference(NETD)and signal-to-noise ratio(SNR)of the system is analyzed,and the variation of NETD and SNR with temperature before and after laser damage is calculated,and its rationality is analyzed.4.The experimental study of laser interference television imaging system and visible light imaging camera was carried out.In particular,the edge spread function,line spread function and modulation transfer function are discussed in detail at the different spots of the same edge with different incident laser power density.And the effect of laser interference is analyzed and evaluated by the aspect of image quality.