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 µm without scanning frequencies as in frequency-domain reflectometers of either the continuously or the stepwise-swept variety.
© 1994 Optical Society of America
Naohiro Tan-no, Tsutomu Ichimura, Tadayuki Funaba, Naoki Anndo, and Yoshiki Odagiri, "Optical multimode frequency-domain reflectometer," Opt. Lett. 19, 587-589 (1994)