Pulsed laser diode optical fiber interferometer for absolute distance measurement

摘要

An interferometry system for absolute distance measurement is described. In the system, an optical fiber Mach-Zehnder interferometer with a chirped laser diode is employed to position the measured object. Another interferometer with He-Ne laser is used to measure the optical path difference. The coherence-length of the pulsed multimode laser diode is studied. In the experiments, the system measured the absolute distance up to 1 meter with the accuracy of 2 micrometer.