Waveguide AlInAs/AlGaInAs avalanche photodiode for 20 Gbit/sphotoreceivers

摘要

High speed photodetectors are needed in optical communicationsystems and avalanche photodiodes are essential in highly sensitivephotoreceivers at the 1.55 μm wavelength. Avalanche photodiodes(APDs), when compared to PIN photodiodes, provide higher responsivitiesdue to their internal gain M. An improvement in the signal to noiseratio of about 10 dB is expected at 20 Gbit/s. Very good performanceshave already been demonstrated at 10 Gbit/s. For higher bit-rates, aside-illuminated structure has been proposed, to reach simultaneouslyhigh responsivity and high speed. The simulations allowing to designwaveguide APD structures, their fabrication and their characteristicsare reported in this paper