Optically heterodyne diagnosis of a high-saturation-power undoped InP sandwiched InGaAs p-i-n photodiode grown on GaAs

We demonstrate the optical heterodyne diagnostics and high saturation power characteristics of a novel undoped InP sandwiched In_0.53Ga _0.47As p-i-n photodiode with a partially p-doped photoabsorption layer, which is grown on a linearly graded metamorphic In_xGa _1-xP buffered GaAs substrate layer and exhibits an excellent low dark current density of 3.6×10^-7 A/cm². Such a top-illuminated optical receiver exhibits an illuminating window of 60-μm diameter, which performs ultra-linear power handling capability up to 18 dBm at 1550 nm, providing a maximum photocurrent of 35 mA under a reverse bias of 9 volts. These result in extremely high current bandwidth and bandwidth- responsivity products of 350 mA·GHz and 4.8 GH·A/W, respectively, at receiving frequency of up to 10 GHz.