White Light Shearing Interferometer Using Phase Modulation Module of Michelson Configuration

• Main Authors: Hsieh Hua-Yueh, 謝樺岳
• Other Authors: Lin Shyh-Tsong
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/35m97x

碩士 === 國立臺北科技大學 === 光電工程系研究所 === 103 === This thesis presents a white light shearing interferometer capable of detecting samples using phase-shifting measurement and phase-scanning measurement modes. A white light laser is adopted as the source. It propagates through a phase modulation module (PMM) and then enters the interference module (IM), where an uni-axial birefringent crystal (USC) shears the incoming beam into two beams, and the sample under test reflects the beams back to the USC. The USC shears the incoming beam into two beams, and the sample under test reflects the beams back to the USC. The USC finally recombines the two beams to the USC. The USC finally recombines the two functions. One is to adjust the optical path difference of the interference beams, so it is within the range of coherent length of the interferometer image to do the phase-shifting and phase-scanning measurement modes. Where the phase-shifting mode is available for smooth surface examination, and the phase-scanning mode is available for smooth and piece-wise smooth surface detections. This research has installed the interferometer. And it has been successfully employed for examining the radii of silicon wafers and a concave mirror using the phase-shifting mode; and the step-height of a composed gage-block using the phase-scanning mode.