SENSITIVITY LIMITS OF LONG-WAVELENGTH MONOLITHICALLY INTEGRATED P-I-NJFET PHOTORECEIVERS

Noise characteristics and factors which limit the sensitivity of long- wavelength monolithically integrated photoreceivers using InGaAs p-i-n photodiodes (PD) and InGaAs junction-held-effect transistors (JFET's) were analyzed with regard to the input-noise current and the open-loo p gain. Effects of the JFET gate length and the parasitic capacitance on the sensitivity were also clarified. Three types of photoreceivers were fabricated by using metal organic vapor phase epitaxy (MOVPE) -gr own crystals and Be-ion implantation technology. The receiver using a cascode input stage had an extremely high sensitivity (-35.4 dBm) for a 622-Mb/s NRZ, 1.3-mu m-wavelength signal. The sensitivity of the oth er two receivers using an inverter input stage was moderate, -33.6 dBm for a multipower supply input stage and -31.4 dBm for a single power supply input stage.