Method of interferometry with modulated optical path-length difference and interferometer
    4.
    发明授权
    Method of interferometry with modulated optical path-length difference and interferometer 有权
    具有调制光程差和干涉仪的干涉测量方法

    公开(公告)号:US06958817B1

    公开(公告)日:2005-10-25

    申请号:US10917806

    申请日:2004-08-13

    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.

    摘要翻译: 干涉仪具有用于产生第一光束的源和具有波长λ的相干单色光的第二光束,用于引导光束通过具有路径长度差的两个不同光路的光学元件,用于检测干涉信号的检测器 以及用于周期性地附加地改变路径长度差以允许在λ/ 4的路径长度差周期性附近检测干扰信号的调制器。 因此,可以检测由路径长度差的小周期变化引起的干扰信号的最大强度变化。 通过将路径长度差改变至少λ/ 2引起的最大强度变化也可以是可检测的。 干涉仪可以用于测量小的振动,而不需要预校准和/或用于将路径长度差保持在λ/ 4附近的反馈伺服系统。