发明授权
- 专利标题： Method of interferometry with modulated optical path-length difference and interferometer
- 专利标题（中）： 具有调制光程差和干涉仪的干涉测量方法
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申请号： US10917806申请日： 2004-08-13
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公开(公告)号： US06958817B1公开(公告)日： 2005-10-25
- 发明人: Weiguang Zhu , Zhihong Wang , Chen Chao , Ooi Kiang Tan
- 申请人： Weiguang Zhu , Zhihong Wang , Chen Chao , Ooi Kiang Tan
- 申请人地址： SG Singapore
- 专利权人： Nanyang Technological University
- 当前专利权人： Nanyang Technological University
- 当前专利权人地址： SG Singapore
- 代理机构： Dinsmore & Shohl LLP
- 主分类号： G01B9/02
- IPC分类号： G01B9/02
摘要：
An interferometer has a source for generating a first beam and a second beam of a coherent monochromatic light having a wavelength λ, optical elements for directing the beams through two different optical paths having a path-length difference, a detector for detection of an interference signal of the beams, and a modulator for additionally varying the path-length difference periodically to allow the interference signal be detected near a path-length difference of λ/4 periodically. A maximum intensity change in the interference signal caused by a small period change of the path-length difference is thus detectable. The maximum intensity change caused by varying the path-length difference by at least λ/2 may also be detectable. The interferometer may be used to measure small vibrations, without pre-calibration and/or a feedback servo system for keeping the path-length difference near λ/4.