A novel phase demodulation and projector design method for 3D profile measuring is presented. The system employs a LD as a light source and CCD as a detector. LD and small optical fiber space encoding projector is used to make the system tight and convenient. The light is guided into optical fiber by optical fiber coupler. This method is based on two-optical-fiber interference principle. The projector is made up by six single-mode fibers. Six single-mode fibers are ranged closely into right line to form three pairs of coherent light sources. The space length of every pair of optical fibers is different. The ratio of space length is 1:3:5. Three frames of deformed interference pattern with different spatial frequency are produced. The phase can be demodulated through algebraic operation, arc cosine and phase unwrapping of three frames of interferogram. Theoretical model is established for optical 3D measurement. Phase formula and unwrapping method is given. Numerical simulation and experiment results show that this way is feasible.

Date Published: 27 November 2007
PDF: 6 pages
Proc. SPIE 6723, 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, 672347 (27 November 2007); doi: 10.1117/12.783623

Published in SPIE Proceedings Vol. 6723:
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment
Junhua Pan; James C. Wyant; Hexin Wang, Editor(s)