Reflectivity and photoluminescence have been used to study optical absorption from an absorbing Bragg reflector consisting of AlAs/GaAs Bragg reflector and InGaAs/InGaAsP multiple-quantum-well absorbing layer. An absorption dip due to the optical confinement of the Fabry-Perot resonance was observed in the reflectivity spectrum. Based on the transfer matrix method along with the complex index of refraction, we successfully analyzed the reflectivity spectrum and obtained the absorption coefficient of the absorbing cavity around 1550 nm. We also demonstrated that the quality factor of the Fabry-Perot mode in photoluminescence could be used to estimate the absorption coefficient of the cavity medium in our absorbing Bragg reflector.
- Bragg reflector