Temperature dependence of the reflectivity in absorbing Bragg reflectors.

The reflectivity of absorbing Bragg reflectors consisting of a GaAs/AlAs Bragg mirror and a InGaAs/InGaAsP multiple-quantum-well cavity layer was studied as a function of temperature. An absorption dip in the stop band due to the optical confinement of the Fabry-Perot resonance was observed in the reflectivity spectra. The absorption intensity of the dip increased with temperature and was explained by the resonant coincidence of the Fabry-Perot cavity mode and the quantum-well absorption. The temperature-dependent reflectivity spectra were successfully reproduced using the transfer matrix method and the linear dependence of the refractive index on temperature.