65 GHz InGaAs/InAlGaAs/InP waveguide-integrated photodetectors for the 1.3–1.55 μm wavelength regime

We report on ultrafast waveguide-integrated metal-semiconductor-metal photodetectors based on low pressure metal organic chemical vapor deposition grown semiinsulating InP/InGaAs/InAlGaAs/InP layers. The vertically coupled detectors have an internal coupling efficiency of >90% at 1.3 and 1.55 μm wavelength for detector lengths of 30 μm. A 3 dB bandwidth of 65 GHz at 1.55 μm wavelength is achieved by employing 0.3 μm feature-size finger electrodes and an active layer thickness of 150 nm. Furthermore, we present results on high-performance devices with a buried waveguide structure fabricated by regrowth of InP:Fe.