Optical multimode frequency-domain reflectometer

Abstract

A multimode laser can instantaneously generate a carrier frequency of significantly wide band. The proposed systems, composed of a free-running multimode laser diode, an optical spectrometer, and a computing system for fast Fourier transformation, can easily provide the potential for ultrahigh resolution of the order of 10 microm without scanning frequencies as in frequency-domain reflectometers of either the continuously or the stepwise-swept variety.