Key Techniques For Phase Profilometry Based On Sinusoidal Phase Modulation Fiber-Optic Interferometry

This paper is supported by the National Nature Science Foundation of China,focusing on the dynamic measurement of small-size three-dimensional surfacetopography, researching key technologies of three-dimensional shape measurementmethods which based on sinusoidal phase modulation optical fiber interferometerfringe projection phase-shifting profilometry, including interference fringes phasecalculation technique of sinusoidal phase modulation integrating-bucket method,build using Mach-Zehnder interferometer structure fiber interferometer fringeprojection system to achieve interference fringe projection, by use of the fiber endsFresnel reflection signals and fiber optic Michelsion interferometer structure, designsinusoidal phase modulation optical interference fringe projection phase stabilitycontrol system which can control the interference fringe high-precision phasesinusoidal variation, research the enhance technology of deformed fringe image whichis modulated by height or depth of the measured object. The main contents include:1. Establish fiber interferometer fringe projection, the system can achievehigh-density fringe projection by using Mach-Zehnder interferometer structure andYoung’s double hole interference principle. Build the mathematical model of the fiberinterferometer fringe projection and analysis the projection fringe influenced by thesystem structure parameters.2. In order to measure the phase fluctuations caused by optical phase sensitivityand the outside while the optical interference fringe projection system is undersinusoidal modulating. Design an optical interference fringe projection phasemeasurement system, the systems uses the fiber ends Fresnel reflection signals andfiber optic Michelsion interferometer structure to achieve interferometer fringe phaseshifting measurement.3. Research the effects on integrating-bucket made by phase modulation andphase angle of the modulation signal, and design sinusoidal phase modulation opticalinterference fringe projection stability control system, which add a compensatingsignal to the sinusoidal modulation signal to achieve projection fringe phase precision sinusoidal changes, provide the basis for three-dimensional shape measurementmethods which based on sinusoidal phase modulation phase-shifting profilometry.4. Research the processing of interference fringe image, under the premise thatthe fringe phase doesn’t distorted, maximize the quality of the interference fringes,thereby increasing the accuracy of subsequent phase extraction.