[OPTICAL REVIEW Vol. 4, No. 4 (1997) 442-443]

A Miniaturized Tunable Filter Based on a Fiber Bragg Grating Loaded by a Ceramic-Tube Microheater

Yoshiaki TACHIKAWA, Sinji NAGAOKA and Yoshio SUZUKI

NTT Opto-electronics Laboratories, 9-11, Midori-cho 3-chome, Musashino, Tokyo, 180 Japan

(Received April 23, 1997; Accepted April 28, 1997)

A miniaturized 1.55 μm tunable fiber Bragg grating (FGB) filter is proposed and successfully demonstrated using an aluminum ceramic-tube with a tungsten thick film sleeve microheater. Fine tuning of the Bragg reflective wavelength with 0.0135 nm/°C is achieved by adding the constant thermal distribution along the uniform FBG with a 0.3 nm bandwidth. Furthermore, a 1.5 nm linearly chirped reflection bandwidth is obtained by thermal gradient loading.

Key words : fiber Bragg grating, tunable filter, microheater, thermal loading, thermal gradient, thermo-optic effect, tunable chirping, dispersion equalizing, wavelength division multiplexing