A GaAlAs-GaAs integrated coherence modulator

This paper presents a novel integrated III-V semiconductor waveguide modulator specially designed to generate optical delays of several hundred micrometers. This is achieved by simultaneous propagation of transverse electric (TE) and transverse magnetic (TM) lowest order modes in an original layered waveguide exhibiting a group birefringence greater than 0.02 at 1.3 /spl mu/m. The device has 40% contrast, a switching voltage of 7 V with a 10-mm long electrode and is suitable for transmission and multiplexing of signals by coherence modulation of light in an optical fiber network powered by a short coherence source such as a superluminescent diode.