Study On Coupling Efficiency Of High Mechanical Alignment Between Infrared Optical Fiber Imaging Bundle And Micro-Lens Array

In the field of high-resolution infrared remote sensing imaging technology,the bottleneck of manufacturing technology of the ultra-long-line infrared charge coupled device(CCD)limits the high-resolution ground imaging of the satellite-borne remote sensing camera.By connecting the "line-surface" conversion heterogenic optical fiber imaging bundle(OFIB)in series in the optical path,the ultra-high-resolution infrared image of the long-line optical fiber bundle can be obtained by the area array CCD.This thesis studies the assembly coupling technology of the micro-lens array and the OFIB,which lays the foundation for the application of infrared optical fiber bundles with high-coupling efficiency in satellite-borne high-resolution remote sensing cameras.In this study,a model of a heterogenic high-coupling efficiency infrared optical fiber imaging system with a micro-lens array and an OFIB as an assembly was established.Based on its mechanical alignment error principle,this experiment investigated the variation rule of the coupling efficiency of different error margin coefficients and mechanical alignment coupling efficiency.The correlation among error margin,core diameter,error margin coefficient and the field of view angle of the optical fiber imaging system was obtained.Based on these results,the key parameter design and simulation research of the image transmission system was carried out,the accuracy of the design of system parameter was verified,and the ideal assembly coupling effect was obtained.The computer vision technology has been employed to extract the key parameters of the micro-array structure,achieving effective filtering of noise points and spots in the image and then solving the recognition and renovation of contour of large-scale fiber array and difficulty in high-precision and high-efficiency extract of parameters in the central point under high noise background.It is concluded that the cumulative error of the array spacing at the end of the optical fiber bundle is 6.42?m.Based on this result,the error margin coefficient is infered to be 1.25,and the theoretical mechanical alignment coupling efficiency of the image input assembly was calculated to be 98.67%.A high-precision mechanical alignment coupling efficiency measurement system composed of precision 6-DOF coupling assembly and adjustment subsystem and infrared radiation energy measurement subsystem was established.Through kinematic analysis,the maximum positioning error of the system is smaller than the lateral mechanical alignment error margin,which satisfies the precise assembly requirements of the micro-lens array and the OFIB.We also developed a high emissivity area-source blackbody target device based on array pyramid structure,which realizes the high performance requirements of the measurement subsystem for the light source.The weak infrared radiation energy at the image output end of the OFIB is collected by the integrating sphere,and the output power measurement of the measurement system under different coupling states of the assembly was realized.The actual mechanical alignment coupling efficiency at the image input end is 92.65%,and the light energy utilization of the optical fiber bundle was increased by 64.71%,which greatly optimizes the performance of the OFIB system.