Abstract
A subnanometer resolution displacement sensor based on a grating interferometric cavity with intensity compensation and phase modulation is proposed and experimentally demonstrated in this paper. The grating interferometric cavity is composed of a frequency-stabilized laser source, a diffraction grating, and a mirror. To realize a subnanometer resolution, the intensity compensation and phase modulation technique are introduced, which are achieved by an intensity compensation light path, three closed placed photodetectors, a processing circuit and a piezoelectric ceramic transducer, and a lock-in amplifier. The intensity compensation technique can improve the stability of the output intensity signal greatly while the phase modulation technique can increase the signal-to-noise ratio dramatically. The detected signal is intensity modulated and processed by a particular arithmetic circuit. Experimental results indicate that the sensitivity of this displacement sensor is 44.75 mV/nm and the highest resolution can reach 0.017 nm, which is 27 times better than the one without intensity compensation and phase modulation. As a high-performance sensor with immunity to electromagnetic interference, this displacement sensor has potential to be used in nanoscience and technology.
© 2015 Optical Society of America
Full Article | PDF ArticleMore Like This
Shuangshuang Zhao, Changlun Hou, Jian Bai, Guoguang Yang, and Feng Tian
Appl. Opt. 50(10) 1413-1416 (2011)
Atsushi Shimamoto and Kohichi Tanaka
Appl. Opt. 34(25) 5854-5860 (1995)
Dongmei Guo, Ming Wang, and Hui Hao
Appl. Opt. 54(31) 9320-9325 (2015)