[OPTICAL REVIEW Vol. 16, No. 4 (2009) 492-494]
© 2009 The Optical Society of Japan
Alternative Method of Wavelength Drift Free Dual-Wavelength Heterodyne Interferometry for the Absolute Distance Measurement
Kun-Huang CHEN*, Jing-Heng CHEN1, Chi-Chang WU, and Wei-Yao CHANG
Department of Electrical Engineering, Feng Chia University, 100 Wenhwa Road, Seatwen, Taichung 40724, Taiwan, R.O.C.
1Department of Photonics, Feng Chia University, 100 Wenhwa Road, Seatwen, Taichung 40724, Taiwan, R.O.C.
(Received July 15, 2008; Accepted April 6, 2009)
Based on the technique of dual-wavelength and principle of heterodyne interferometry, a modified method for measuring the absolute distance is proposed. Because two test lights suffer from the same influence of wavelength drift in the measurement setup, the minus effect coming from the wavelength drift can be offset. Therefore, the measurement accuracy can be significantly increased. The feasibility of this method was demonstrated with a measurement resolution of about 1.50 μm. This method provides the advantages of a simple optical setup, easy operation and rapid measurement.
Key words: heterodyne interferometry, absolute distance, dual-wavelength, phase difference
*E-mail address: chenkh@fcu.edu.tw