Research On The Response Characteristics And Mechanism Of Pyroelectric Infrared Detector Exposed To Intense Electromagnetic Pulses

Pyroelectric infrared detector,which is characterized as small size,light weight unrefrigerated and broad wave band for detection,has been widely used in night-vision goggles,alarm system,imaging system and other occasions.However,under the increasingly complex electromagnetic environment,guaranteeing the pyroelectric infrared detector to work efficiently is urgent to be solved.Based on the theoretical analysis,numerical simulation and experiment,the paper researches on response characteristics of pyroelectric infrared detector under the strong electromagnetic pulse.Analyzing the polarization and the dielectric relaxation process of pyroelectric materials(LiTaO₃)binding with the linear and nonlinear phenomena appeared in the process of response.And the results have remarkably practical significance.The main work is as follows:1.With classic pyroelectric detector response model and the original parameters of the detector in the experiment,the frequency response characteristic of pyroelectric detector is explained by using the sine wave,square wave function.Hence,the response characteristic curves of the pyroelectric detector are obtained when the detector is exposed to intense electromagnetic pulses.2.Carrying out S?C band irradiation experiment under the different microwave power,pulse width.The paper finds that the response characteristics of the detector are different from the traditional pyroelectric response mechanism,namely the response characteristics time of the pyroelectric detector usually is designed as millisecond magnitude,when the power of microwave exceeds a certain value,the response characteristics time of the pyroelectric detector is second order of magnitude.It is shown that the nonlinear response characteristics of the pyroelectric detector and the polarization mechanism of the pyroelectric detector are different from the classical response characteristics when the pyroelectric detector is exposed to infrared radiation.3.Based on the experimental data,investigating the response mechanism of pyroelectric infrared detector when it is exposed to the intense electromagnetic pulses.Emphatically,analyzing the reasons for the emergence of nonlinear phenomena in the response process.The characteristics of the pyroelectric material(LiTaO₃)and the dielectric relaxation process under the intense electromagnetic pulse are investigated,which shows that the space charge polarization is the main cause of the nonlinear response process.4.In the original S?C band experiments,the maximum E field strengths of pyroelectric detectors'sensitive surface achieves approximately 30 k V/m,a novel waveguide is produced to obtain the response characteristics of the pyroelectric detector exposed to higher E field strengths,subsequently its feasibility is verified by measuring S parameters of the waveguide under different condition.