High-speed InGaAs/InAlGaAs/InP waveguide-integratedMSM photodetectors for 1.3 – 1.55 µm wavelength range

Waveguide-integrated metal-semiconductor-metal photodetectors based on MOCVD-grown InP/InGaAs/InAlGaAs/InP layers are reported. The evanescent field coupled detectors have an absorbing layer thickness of only 150 nm, and 0.7 µm feature-size electrodes. An internal coupling efficiency of ≥ 90% has been achieved for detector lengths as short as 20 and 30 µm at wavelengths of 1.3 and 1.55 µm, respectively. A 3 dB bandwidth of 20 GHz at 1.55 µm has been obtained.