Reflectivity and photoluminescence studies in Bragg reflectors with absorbing layers

Reflectivity and photoluminescence studies on the GaAs/AIAs Bragg mirror wi th the InGaAs/InGaAsP multiple quantum well absorbing cover layer were perf ormed at a wavelength of 1550 nm. An absorption dip enhanced by optical con finement of the Fabry-Perot resonance was observed in the reflectivity spec tra. The refractive indexes of the AlAs/GaAs quarter-wave stacks and cover layer were obtained by tuning the angle of incidence tin reflectivity) and angle of detection (in photoluminescence) in the Bragg reflector, respectiv ely. The photoluminescence studies also provide a vehicle for obtaining the absorption coefficient of the cavity medium by measuring the quality facto r of the Fabry-Perot mode.