Information Processing Of Optical Wave Phase-shifting Technology

The optical phase shifting interferometry is an integrated technology of the combinationof optical phase shifter,interferometer,computer and image acquisition devic.Thetechnological characteristic is accuracy and high resolution ratio,now it widely used fieldsof the surface shape measure of optical surfaces,surface smooyhness measure,optical imagingquality evaluation,optical image encryption,digital holography technology, and so on.Due to shift phase interferometer is susceptible to interference from the externalenvironment, vibration and airflow in the process of using, resulting in most laboratoryconditions can’t guarantee the measurement accuracy, which limits their application.To dealwith this technical defects, many researchers have come up with variety of experimentalprograms and calculation methods to reduce the adverse effects of the experimentalenvironment interference. We done a lot of theoretical and experimental studies in this area,the main work is as follows:1.The use of the spatial light modulator as phase shifters, it can be achieved quickly andaccurately optical wave phase shift.This technological characteristic is as requested by thegrating of the modulator,the direction along perpendicular to the grating stripes catty outaccurate translation, good time stability, good repeatability.2.Using computer imaging technology produce a grating pattern, this technique canaccurately control to change the parameters of the grating pattern(such as the spatialfrequency, fringe contrast and transmittance,and so on). Different phase grating input to thespatial light modulator can change the correspondin lightwave phase; achieve the exact phasemodulation of the light wave.3. It is a Mach-Zehnder interferometer used to measure the light wave phase,the CCDcarry out continuous acquisition for interference fringe image of the interferometer output.The computer control the CCD to achieve a continuous acquisition speed of the interferencefringe image with with displayeing alternately corresponding grating pattern in the spatiallight modulator match.4. Using computer program process the continuous acquisition interference fringe image,search two interferences fringe image retardation which will be close to raster display lightmodulator phase shift value.