Abstract

Photodetectors for long-wavelength operation have been realized on silicon as discrete devices^1–2 in combination with SOI waveguides³ and in combination with SiGe waveguides as MSM diodes.⁴ In this work the lateral MSM diodes have been replaced by vertical P-I-N diodes with a similar SiGe multiple-quantum-well structure that maintains a low reflection coefficient at the waveguide-photodetector transition, which is important for applications with respect to an optical coherent receiver. The P-I-N diodes permit lower dark currents and higher internal electric fields than can be obtained with MSM diodes having Schottky barriers of approximately 0.5 eV.

© 1993 Optical Society of America