Title :
A phase encoding method for improving the resolution and reliability of laser interferometers [displacement measurement]
Author :
Hagiwara, Nobumi ; Nishitani, Youhei ; Yanase, Masaru ; Saegusa, Takeo
Author_Institution :
Dept. of Electr. Eng., Nat. Defense Acad., Yokosuka, Japan
fDate :
4/1/1989 12:00:00 AM
Abstract :
An electronic method is proposed for improving the resolution and reliability of a laser interferometer commonly used for measuring displacement. By assigning code numbers to the divided segments of the interference fringe interval, the displacement of the moving device is measured with 1/170 of the lightwave length resolution (about 4 nm with He-Ne laser). Since the error caused by environmental noise is not integrated in the counting process, the measured values become more reliable than those of conventional pulse-counting methods
Keywords :
displacement measurement; encoding; helium; light interference; light interferometers; measurement by laser beam; neon; reliability; He-Ne; code numbers; displacement measurement; environmental noise; interference fringe interval; laser interferometers; phase encoding; reliability; Displacement measurement; Encoding; Interference; Interferometers; Interpolation; Optical interferometry; Optical noise; Pulse measurements; Read only memory; Stimulated emission;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
