High-speed, high-power 1.55 μm photodetectors

High-speed, high-power photodetectors are required in 40 Gbit/s front-ends as well as for optic/millimeterwave-conversion in 60 GHz broadband mobile systems. The demand for a high bandwidth maintained up to high power levels is fulfilled by waveguide-integrated p-i-n diodes on InP. These photodetectors exhibit a cutoff frequency above 50 GHz. By monolithic integration of a spot size transformer a responsivity of 0.7 A/W is achieved and the fiber alignment tolerances are increased by one order of magnitude. Linear power behaviour up to +12 dBm at 50 GHz and maximum output voltage swings of 1 V are demonstrated.