1 September 2001 Influence of object roughness on specimen gratings for moire interferometry
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Moire interferometry is a high-sensitivity method for whole- field, in-plane displacement measuring. This technique requires the surface under test to be mirror-like and prepared with a fine diffraction grating (typically ~1200 lines/mm). Gratings are commonly made of photoresist. However, if we want to analyze engineering structures, to have a surface without preparation under polishing, the surface roughness is an important parameter to be characterized. We analyze the fringe visibility of moire during the fabrication of specimen gratings in function of the surface object roughness. The surface object target is impregnated with photoresist Shipley S1822. Two beams from a He-Cd laser illuminating the surface target are used to record the specimen grating. With a similar optical system we use a He-Ne laser to obtain a virtual grating and consequently the interferometric moire fringes. Through the correlation length and basic statistical the surface roughness is characterized.
© (2001) Society of Photo-Optical Instrumentation Engineers (SPIE)
Amalia Garcia Martinez, Ramon Rodriguez-Vera, J. A. Rayas, Jose Vazquez-Luna, "Influence of object roughness on specimen gratings for moire interferometry," Optical Engineering 40(9), (1 September 2001). https://doi.org/10.1117/1.1394738 . Submission:

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