Multi-wavelength Interference Simulation Of Fiber Based On DMD

The topography of measuring instrument is a device that can measure the threedimensional topography and deformation of object surface.It can be used not only to measure the topography of micro-electronics,micro-machines and other microstructures,but also to measure the topography of large mechanical components.It is widely used in industrial production.There are two types of topographic measuring instruments: contact and non-contact.The traditional contact of measuring instrument has a mechanical probe.When measuring,the probe can be in contact with the surface of the object,and it is so easy to scratch the surface of the object after measuring that can damage to the surface topography of the object,reducing the measuring accuracy of the object.The non-contact of measuring instrument is based on photoelectric technology,measuring the surface topography of the object without touching the surface of the object,overcoming the defects of contact measuring.Among them,optical fiber interferometry has a high longitudinal resolution,which can achieve the measurement accuracy of less than 1nm,but what the point-scanning of measurement method is that needs to be equipped with a high-precision displacement platform,the measurement accuracy is affected by the lateral resolution,the measuring of time is longer,and the measuring of environment requirement is higher,it can not achieve the measuring for long-distance objects.In order to solve the above problems,based on fiber optic interference technology,this paper introduced a measuring system with the combination of fiber-optic non-scanning multi-wavelength and DMD detector.When measuring,what the light in the probe is that covers the surface of the object,which can directly generate the three-dimensional image of the measured object by modulating the DMD.It greatly improves measurement efficiency.This paper introduced an improved measuring system that consists of some optical devices,such as fiber coupler,FBG fiber grating,DMD detector and so on.The system,using the characteristics of FBG reflecting only Bragg wavelength to separate the self-mixing interference signals of each wavelength,using multi-wavelength interference to increase the measurement range,using the single-photon array that can detect the minimum energy of light,and realize the imaging spectrum by linear array or Singlephoton detector of array Geiger mode to obtain spectral dimension information,that realizes non-scanning measuring.The simulation results that verify the feasibility of the measuring system and realize the measuring method without scanning.Different reconstruction algorithms are used to analyze the accuracy in order to reconstruct the target image.I analyze the anti-interference of the system by adding noise and denoising.The measurement accuracy of the system is analyzed by measuring regular objects and irregular objects.