Yoshitaka TAKAHASHI^*, Shinji SEKIYA and Nobuhiro IWAI^†

Department of Electronic Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan

(Received January 30, 2003; Accepted May 6, 2003)

A bi-directional fiber ring laser with a semiconductor optical amplifier has been developed in which a frequency difference between the counter-propagating oscillations is controlled by an introduced birefringent medium. With the material which causes the retardation change by a physical phenomenon to be measured, the laser in this study is applicable to a novel fiber sensor of which the sensing signal is obtained in a frequency domain.

Key words: ring laser, fiber laser, semiconductor optical amplifier, optical sensing, optical fiber sensor

^*E-mail address: taka@el.gunma-u.ac.jp
^†Present address: Panasonic Mobile Communications Co., Ltd., 3-1, Tsunashima-higashi 4-chome, Kohoku-ku, Yokohama 223-8639, Japan.