Laser diode interferometer used for measuring displacements in large range with a nanometer accuracy

✍ Scribed by Xuefeng Wang; Xiangzhao Wang; Hongbin Lu; Feng Qian; Yang Bu

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 130 KB
• Volume: 33
• Category: Article
• ISSN: 0030-3992
• DOI: 10.1016/s0030-3992(01)00027-5

✦ Synopsis

In this paper, the displacement of an object is measured with a photothermal phase-modulating laser diode interferometer. A feedback control system is designed to reduce the measurement errors caused by the uctuations in the optical wavelength of the laser diode and the vibrations of the optical components in the interferometer. A new method is proposed to enlarge the measuring range of displacement. Using this method, the measuring range is enlarged from half wavelength to nearly 125 m and the measurement accuracy is about 1 nm. The simulation and experimental results have shown the usefulness of the method and the feedback control system.