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(0.53)Ga(0.47)As p-i-n photodiode with a partially p-doped photoabsorption layer, which is grown on a linearly graded metamorphic In(x)Ga(1-x)P buffered GaAs substrate layer and exhibits an excellent low dark current density of 3.6x10(-7) A/cm(2). Such a top-illuminated optical receiver exhibits an illuminating window of 60-mum 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 GHz*A/W, respectively, at receiving frequency of up to 10 GHz.