Thermal crosstalk in integrated laser-Modulators

A monolithically integrated distributed feedback laser with an electroabsorption modulator has been investigated showing a redshift of emission wavelength with applied modulator bias voltage. This leads to an adiabatic chirp parameter /spl alpha//sub H/ of up to 0.13 that is usually zero for decoupled devices like hybrid laser modulator integrations. By measurement and corresponding simulation, the phenomenon was identified to be caused by thermal coupling between the sections.