Guo Dongmei, Wang Ming, Hao Hui
Appl Opt. 2015 Nov 1;54(31):9320-5. doi: 10.1364/AO.54.009320.
A novel laser feedback grating interferometer (LFGI) with a phase-generated carrier demodulation technique is proposed in this paper. Laser feedback grating interference occurs when light emitted from a laser is diffracted by the double-diffraction system and re-enters the laser active cavity, thus generating a modulation of the lasing field. In order to improve the displacement measurement resolution, phase modulation is introduced by an electro-optic modulator in the external cavity of the LFGI. Detection of the displacement can be easily achieved by the time-domain orthogonal demodulation, which does not involve any complicated calculation and is insensitive to the sampling error. Experimental results show that the proposed system has a general nanometer-level resolution. It provides a potential displacement sensor with high resolution, simple mechanical structure, and good reliability.
本文提出了一种采用相位载波解调技术的新型激光反馈光栅干涉仪（LFGI）。当激光器发出的光被双衍射系统衍射并重新进入激光有源腔时，会发生激光反馈光栅干涉，从而产生激光场的调制。为了提高位移测量分辨率，在LFGI的外腔中通过电光调制器引入相位调制。通过时域正交解调可以轻松实现位移检测，该方法不涉及任何复杂计算，并且对采样误差不敏感。实验结果表明，所提出的系统具有一般的纳米级分辨率。它提供了一种具有高分辨率、简单机械结构和良好可靠性的潜在位移传感器。
