Research On Characteristics Of Standard Cone Beam Imaging System For Angle Measurement

In this paper,based on the Fabry-Perot（F-P）etalon multi-beam interference principle of measuring small angle method,the influence of the F-P etalon,imaging objective and reflector on the imaging quality of the interference ring in the optical system are studied theoretically and analyzed experimentally.In order to provide a theoretical basis for the subsequent development of high-accuracy micro-angle measuring instruments.The research work of the thesis mainly include the following parts:（1）Based on the principle of multi-beam interference of F-P etalon,the standard conical beam emitted is used as the measuring beam to research principle and method of achieving small angles,and analyze the characteristics of multi-beam interference.At the same time,the principle of measuring the distance d of F-P etalon with three-wavelength decimal method is introduced.The experimental device for measuring the interference ring is built according to the imaging principle of F-P etalon.（2）Based on the multi-beam interference model,the effects of incident wavelength,focal length,reflectivity of F-P etalon,refractive index and spacing of the spacer layer on the imaging ring are simulated and analyzed.Aiming at the light intensity of the imaging ring,a simulation analysis of the transmittance of possible defects such as absorption loss,uneven surface and imprecise parallelism of the F-P etalon interference plate.And analyze the effect of ambient temperature on the center wavelength drift of solid etalons and air gap etalons.At last,the three-wavelength decimal repetition method is improved by modifying the reflection phase shift factor,and the relative uncertainty of the standard spacing is about 9.9×10^-7.（3）Based on the principle of wavefront aberration and distortion measurement,the imaging objective lens measurement method using HSWS is proposed to measure different areas of the imaging objective lens with different focal lengths.The experimental results show that the wavefront aberration and distortion of 75 mm objective lens are better than that of 50 mm objective lens.Under three different spacing F-P etalons,perform interference ring imaging experiment on two imaging objectives separately.The experimental results show that the imaging quality of the75mm imaging objective is better.Imaging experiments with and without reflectors are performed under three different spacing F-P etalons.The results of the three groups of experiments showed that the calculation results with and without the mirrors are not significantly different.The above research results can be directly used to analyze the optical imaging characteristics of the micro-angle measurement system.The factors are the same as those affecting the imaging system,and the influence rules are consistent.