A simple monolithically integrated optical receiver consisting of an optical preamplifier and a p-i-n photodiode

We demonstrate a monolithic optical receiver consisting of the integration of a semiconductor optical amplifier and a p-i-n photodetector based on asymmetric twin-waveguide technology. Multiple quantum wells with 1% compressive strain are used for both optical amplification and detection. The device has a peak external responsivity of 8.2±0.4 A/W (∼9-dB fiber-to-detector gain), and a 3-dB optical bandwidth of 11±1GHz, equivalent to a 265-GHz gain-bandwidth product. The efficient coupling of light between individual optical components is achieved by a lateral adiabatic taper that reduces the fabrication complexity. This work represents a considerable simplification over previously demonstrated high-performance integrated optical receivers.