[OPTICAL REVIEW Vol. 10, No. 1 (2003) 38-42]
© 2003 The Optical Society of Japan
Applying a Mode Selector to Improve the Pulse-Compression Performance of Asymmetric-Coupled-Waveguide-Based Dispersion Compensators
Yong LEE, Kazuhiko HOSOMI, Hiroyuki UCHIYAMA1, Toshio KATSUYAMA, Shinya KOMINAMI1 and Tomoyoshi MISHIMA1
Advanced Research Laboratory, Hitachi, Ltd., 1-280 Higashi-Koigakubo, Kokubunji, Tokyo, 185-8601, Japan
(Received August 28, 2002; Accepted October 18, 2002)
An InGaAsP slab-type asymmetric-coupled-waveguide-based dispersion compensator with a mode selector has been designed and fabricated. The mode selector is necessary to select either a symmetric [with a positive group-velocity dispersion (GVD)] or antisymmetric (with a negative GVD) supermode. These supermodes exist simultaneously in the dispersion-compensation region of the device. Pulse-compression experiments were used to test the dispersion compensator, evaluating the function of the mode selector. A theoretical study of the experimental results shows that the mode selector obtains a very strong selectivity (nearly 100%) for the antisymmetric supermode.
Key words: asymmetric coupled waveguide, dispersion compensator, mode selector, pulse compression, symmetric supermode, antisymmetric supermode