Research Of Passive Detection Incident Direction And Spectral Information Of Short Pulse Laser

Military Short pulse laser detection technology is the core of the laser warning system(LWS). It is the difficulty and promise of LWS, real-time and accurately acquiring theincident direction and spectral information of the incident short pulse laser. In this dissertation,some key problems of the laser warning technology have been studied based on the analysisof existing laser warning technology. The main research contents of the paper as show below:First, a detection system model of short pulse laser incident direction and spectral information withwide field of view was established, based on the research of short pulse laser application inmilitary and the development tendency of detection technology. The model may realize thequickly detecting incident short pulse laser, comprehensive using the theories andtechnologies of optical fiber and optic-electronic detection and static Fourier transform and soon.Second, a optical receiver head model have been established to precisely and equablydivide the space field of view (FOV), with6triangle windows and6trapezoidal shapewindows. It can overcome the defect using circular window which can cause the unevenoverlapping FOV of adjacent windows and even scotoma. Some factors have been analyzedin theory such as size and shape of windows, fixed position of photo detector, windowmaterial, lens etc, and correspond experiment have been done, result showed that we realizedhemisphere FOV space divided into36equal parts, with6triangle windows and6trapezoidalshape windows, and the resolution reached30°.Third, a tapered and lensed fiber have been designed in order to increase the FOV, and itstheoretical model have been established to analyze the relations of the fiber’s FOV with thefiber cone angle and the size of lens and focus length. The FOV can achieve116°, if we use double quartz fiber with NA0.22and cone angle116°. In experiment, we designed severalTLF and tested their performance, and the result showed that maximal FOV of single TLF is110°.Forth, a theoretical model was established of laser propagation and photoelectricconversion and signal amplification and noise analysis to discuss the effect of air quality andphotoelectric device and signal processing circuits on the detection performance. We designedthe experiment system and corresponds optical and electric circuits to verify the validity ofthe model.Fifth, a new static Fourier transform interference etalon model have been present in thepaper, we analyzed its working principle and proved its various performance in theory. Anexperimental system has been designed to test quickly the spectral information of laser basedon the etalon. Several semiconductor lasers emission have been tested using the experimentalsystem, and compared the result with spectral information obtained by using the Q8344Aspectrometer made in Japan, the result showed that the experimental system can obtain thecorrect spectral information. At last, a spectral resolution enhance method has beet putforward according to the static Fourier transform interference etalon based on repeated use ofinterferogram, and its advantage and disadvantage has been discussed in theory.