Key Technology Research Of Optical Scanning Long Trace Profiler

Ultra-smooth off-axis aspheric cylindrical mainly applied in Soft X-Ray/EUVoptical system of grazing, which is the main structure of X-ray telescope system forSpace weather forecast。Currently, surface measurement is key and difficult ofaspheric cylindrical developping. Due to lack of cylindrical aspheric surface shapemeasurement method and apparatus in the country, which Seriously hampereddevelopment of soft X-ray space telescope and the related optical instruments andequipment. Pencil beam interference scanning method is currently one ofinternationally advanced technologies of unconventional shape measurement optics.For off-axis aspheric cylindrical measurement, we based on pencil beaminterference principle designed a three-dimensional scanning long traceprofiler(LTP). Compared to the existing LTP, the profiler uses a new beam splittingdevice called beam modulator, Theoretical analysis and MATLAB simulation resultsshow that the beam modulator can achieve higher measurement accuracy; Whilethree-dimensional scanning long trace profiler system changes the operating mode ofrail and turntable, which can Effectively avoid the tested surface deformed by itsown gravity in the measurement. the optical structure of LTP was simulated byZEMAX software in the paper, Simulation results show that the three-dimensionalscanning LTP is feasible, Besides self-designed lens collimator and FT lens fulfillsLTP measurement accuracy requirements. For three-dimensional scanning LTP error sources, the paper classifies them first,then putting a precise analysis of error sourcesthat impact greater and proposing the corresponding correction method. Because theentire three-dimensional scanning LTP device haven’t yet reached fully, We useexisting components to build a two-dimensional LTP measurement structure, Mainlyin order to detect size and shape of the interference fringes on the CCD and LTPsystem stability, Preparing for the ultimate three-dimensional scanning LTP opticalbench. In the measurement data processing, Using Arms spin filtering and Thresholdfiltering to filter for interference fringes, then using sign two-dimensional derivativevalue method for rough positioning and polynomial fitting for fine positioning offringes, the Positioning accuracy can be up to0.1pixels. Selecting severalintegration algorithm to reconstruct the tested surface and Using surface evaluationfunction such as RMS roughness, PV, power spectral density，correlation functionand so on to evaluate the tested surface. IN view of three-dimensional face can’t bemeasured by current experiment, We simulated a cylindrical parabolic mirror, usingthe above several integration algorithms for its face reconstructed, While takingadvantage of surface evaluation function to evaluate the reconstructed surface, theevaluation results is used To test the performance of various integration algorithm.