A GaAlAs-GaAs integrated coherence modulator

This paper presents a novel integrated LII-V semiconductor waveguide modula tor specially designed to generate optical delays of several hundred microm eters, 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 mu m. The device has 40% contrast, a switching voltage of 7 V with a 10-mm long e lectrode and is suitable for transmission and multiplexing of signals by co herence modulation of light in an optical fiber network powered by a short coherence source such as a superluminescent diode.