Abstract

Even for lightwave transmission systems above 10 Gbit/s, highly sensitive and compact photoreceivers are preferable. An avalanche photodiode (APD) with a large gain-bandwidth (GB) product would be one of the most promising candidates for receivers in systems with such extremely high bit rates, as well as in systems with lower bit rates.¹ Recently, we reported a superlattice (SL) APD with a GB product of 80 GHz under a 3-dB bandwidth of 12 GHz,² where the SL allowed us to enhance the ionization-rate ratio for achieving the high GB product.³ To improve the GB product further, it is necessary to reduce the SL multiplication-layer thickness⁴ by overcoming the problem of the accompanying tunneling breakdown with thinning of the SL layer thickness. Here, we demonstrate an InAlAs/InGaAs SL-APD with a GB product of 130 GHz under a 3-dB bandwidth of 12 GHz by introducing a novel SL structure of less than 0.2-µm thickness.

© 1993 Optical Society of America