N-type doping induced losses in 1.3/1.55 /spl mu/m distributed Bragg reflectors

The effect of n-type doping on the peak reflectivity of InGaAsP/InP as well as GaAs/AlAs distributed Bragg reflectors for long-wavelength vertical-cavity lasers has been investigated. A variety of mirrors with different doping levels were grown in both material systems using metal organic vapour phase epitaxy. The reflectance of the structures was measured with high accuracy employing two independent measurement techniques. While nominally undoped DBRs exhibit an expected reflectivity in excess of 99.9%, doping is found to induce significant losses resulting in up to 0.6% reduced reflectance.