Shinji NISHIMURA, Hiroaki INOUE and Shigehisa TANAKA

RWCP Optoelectronics Hitachi Laboratory, Central Research Laboratory, Hitachi, Ltd., 1-280, Higashi-Koigakubo, Kokubunji, Tokyo, 185 Japan

(Received March 16, 1995; Accepted May 16, 1995)

A waveguide-type optical frequency shifter based on a rotating half-wave plate is proposed. The underlying principle can be used to realize a bit-rate-free and modulation-code-free optical frequency shifter. The waveguide was formed along the <1 1 1> direction on a GaAs (1 1 0) substrate by molecular beam epitaxy (MBE) and reactive ion beam etching (RIBE). A 10-MHz optical frequency shift with 16 V_p-p applied voltage and 22.5% shift efficiency is demonstrated.

Key words : frequency shifter, (1 1 0) GaAs, Pockels effect, bit-rate free, modulation code free