Temperature-dependent polarization characteristics of composite-resonator vertical-cavity lasers

We investigate the output characteristics from 10°C to 160°C of a monolithic dual-resonator vertical-cavity laser composed of three distributed Bragg reflector mirrors that separate two nominally identical optical cavities. The light output from the top ion-implanted cavity under forward bias is partitioned into two orthogonal polarizations of the fundamental transverse mode. A reverse bias of sufficient magnitude applied to the bottom oxide cavity causes the abrupt suppression of the dominant polarization and simultaneous emergence of the orthogonal polarization, consistent with wavelength dependent electroabsorptive loss in the reverse biased quantum wells of the oxide-confined cavity. We calculate the internal loss as a function of reverse bias and temperature, and characterize the polarization properties of the device based on the temperature dependence of the laser output. The polarization switching is consistent with increasing absorption with increasing temperature and decreasing absorption at longer wavelengths.