Abstract

Optical waveguide modulators operating at 1.5-μm wavelength are important optoelectronic devices that can be used to extend the bandwidth-distance capacity of optical fiber transmission systems. Multiple quantum-well (MQW) absorption type waveguide modulators fabricated in InP substrates and operating near 1.5-μm wavelength have been demonstrated^1-4 by using various material and growth systems. Previous experimental work on 1.5-μm MQW waveguides has primarily examined the modulation performance of TG polarized light (light polarized parallel to the MQW layers); not as much attention has been paid to the TM polarization. For an InGaAs/InAlAs MQW waveguide modulator, the polarization dependence of the electroabsorption has been reported⁵ with similar modulation performance for both polarizations. In this paper an In_0.53Ga_0.47As/InP (from nowon referred to asInGaAs/InPridge-waveguide MQW absorption modulator is described at an operating laser wavelength of 1.52 μm. In contrast to previous work⁵ the modulation performance of the TM polarization is found to be superior to that of the TE mode. Experimental data showing optical absorption saturation of this device for both polarizations is also presented.

© 1990 Optical Society of America