Design Of Optical System For Monitoring Based On Optical Fiber

Aero-engines are often exposed to radiation and electromagnetic interference in the working environment of the ground testing.Therefore,image acquisition systems require the use of anti-radiation lens materials,higher cost and less variety.The optical fiber image transmission system uses the optical fiber image transmission bundle to connect the frontend objective lens and the back-end coupling lens for collecting images,it has the advantages of radiation resistance,electromagnetic interference prevention,softness and light weight.The optical path bending transmission is realized,also it can greatly simplify the structure of the long light course system,and the system is widely used in military and civilian applications.Based on the analysis of the development status of optical fiber image transmission system at home and abroad,the working principle of optical fiber image transmission optical system is described,and the overall design scheme of optical system is proposed.The purpose of this paper is to observe the target height of 300-3000 mm at a distance of 10 m.Therefore,it is necessary to select large cross section image bundle.The final selected image bundle cross-section size is 6 mm×6 mm,the arrangement is a regular hexagon,the diameter of the monofilament is 10?m,and the number of pixels is on the order of 400,000.The design of the zoom optical system focusing on the front-end objective lens.According to the actual requirements,the parameters of the system are calculated,the relative aperture is 1/5,the focal length ranges from 28 mm to 280 mm.Using the ZEMAX software design system,the final design of the front-end objective lens is composed by 15 spherical lenses,the system conjugate distance is 270 mm,the relative distortion of each field of view is less than 2%,the modulation transfer function(MTF)is greater than 0.3 at the spatial frequency of 70 7)/8)8),and the energy concentration is high.The cam curve fitting and tolerance analysis are carried out for the design results,and the result is good for subsequent machining and setting up.The wavelength division multiplexing system is designed to improve the image transmission information,the main idea is that one fiber transmits multiple image information,and each image information is transmitted through multiple fibers,it is a good solution to the situation that the image is inferior due to broken wire and dark wire in the optical fiber image transmission bundle.Using the improved flat field correction method to deal with image reticulation,the basic idea is to collect dark bottom and uniform background images to extract image defects,next,the processed image is subjected to flat field correction,after the correction,the image texture disappeared and the processing result was good.