Mode coupling in a narrow spectral bandwidth quantum-dot microcavity photodetector

The resonant-cavity photodetector based on a quantum-dot (QD) absorbing region is analyzed and compared with experiment. We show that mode matching due to the low loss cavity in this type of photodetector is important in establishing the detection efficiency. In addition to extending GaAs-based photodetectors into the 1.3-μm wavelength regime, the QD active region can achieve an ultra-narrow spectral response because of its low absorption.