[OPTICAL REVIEW Vol. 18, No. 6 (2011) 455-457]
© 2011 The Japan Society of Applied Physics

High-Speed Scanning Fiber-Optic Heterodyne Interferometer Using a Micro-Electro-Mechanical System Mirror and an f-theta Lens

Long GAO1*, Chunhui WANG1, Yiqin JI2, Yanchao LI1, and Yang QU1

1National Key Laboratory of Science and Technology on Tunable laser, Harbin Institute of Technology, Harbin 150001, China
2Tianjin Key Laboratory of Optical Thin Films, Tianjin Jinhang Institute of Technical Physics, Tianjin 300192, China

(Received June 11, 2011; Accepted September 3, 2011)

This paper describes a novel fiber-coupled heterodyne interferometer using a micro-electro-mechanical system (MEMS) mirror and an f-theta lens. In this interferometer system, the cross-polarized laser beams operating at 2 μm with the frequency difference of 100 kHz are introduced by means of the two acousto-optic modulators (AOM). The sample with diameter of 300 mm is uniformly scanned by the 1 mm laser beam with the help of the combined optical scanning configuration, a MEMS mirror and an f-theta lens. The output intermediate signal from the two channels, reference channel and the measurement channel, are processed in the 12 bit analog-to-digital (A/D) process system. Details of our interferometer scheme are discussed.

Key words: heterodyne interferometer, MEMS mirror, f-theta lens, optical scanning

*E-mail address: gaolong526@yahoo.cn