It is difficult in interferometric metrology to maintain high spatial resolution over a large field of view. In this paper this characteristic is achieved by scanning two focused laser beams over an object surface and a reference mirror surface, respectively, with a rotating mirror, a lens, and a polarization beam splitter. An electric-optic phase modulator generates the phase difference of a sinusoidal waveform of 10 MHz between the two focused beams. Sinusoidal phase-modulating interferometry is used to calculate the phase of the interference signal caused by the two focused beams. The scanning speed of the beams is 20 m/s, and the sampling interval of the interference signal is 1/80 microseconds. The spatial resolution is 2.0 microns over the measurement region of 18.8mm. The measurement results show that the measurement error is less than 5nm.
内容記述
Optoelectronic measurement technology and systems : 6-9 November 2011 : Beijing, China
雑誌名
Proceedings of SPIE - the International Society for Optical Engineering
巻
8201
ページ
82010J-1 - 82010J-7
発行年
2011-11
出版者
International Society for Optical Engineering, SPIE
ISSN
0277786X
書誌レコードID
AA10619755
DOI
info:doi/10.1117/12.910102
権利
Copyright(C)2011 Society of Photo-Optical Instrumentation Engineers
Beam scanning laser interferometer with high spatial resolution over a large field of view
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