Naoto KISHI, Masahiro SAKAUCHI, Takahumi SANO and Eikichi YAMASHITA

Department of Electronic Engineering, The University of Electro-communications, 1-5-1, Chofugaoka, Chofu, Tokyo, 182 Japan

(Received July 1, 1996; Accepted September 12, 1996)

A fiber-optic transceiver which is particularly suitable for long range optical time-domain reflectometers is proposed. An active fiber ring employed in the proposed configuration has both transmitter and receiver functions. The active fiber ring acts as a Q-switched pulse laser source in the transmitter whereas it acts as an optical preamplifier in the receiver. Experimental results on the reflection detection of several lengths of optical fibers have confirmed the operation principle of the proposed scheme.

Key words : OTDR, fiber laser, Q-switch, fiber amplifier, active fiber ring