Monolithic integration of a thin and short metal-semiconductor-metal photodetector with a GaAlAs optical inverted rib waveguide on a GaAs semi-insulating substrate

The first fabrication of a thin and short GaAs metal-semiconductor-metal photodetector monolithically integrated with a GaAlAs optical inverted rib waveguide on a semi-insulating GaAs substrate is reported. An only 0.2-μm-thick and 100-μm-long GaAs absorbing layer is needed to detect 90% of the optical signal at 0.85 μm wavelength. Static, dynamic, and noise measurements have been performed and a bandwidth in excess of 15 GHz is obtained.