Abstract

Avalanche photodiodes (APDs) and p-i-n photodiodes are two of the most widely deployed photodiodes for optical fiber communications. The transit time of photogenerated carriers in p-i-n diodes and that of secondary electrons in avalanche diodes at low gain is the fundamental limit on the bandwidth of these devices. However, conventional structures require a thick absorbing layer to ensure high quantum efficiency. Consequently, while high band widths of 35 GHz have been reported for In_0.53Ga_0.47As p-i-n photodiodes, the use of a 0.5-µm-thick absorbing layer restricted the quantum efficiency to ≤36%.¹

© 1991 Optical Society of America