This paper proposes a method of fabricating planar photodiodes based on var
izonal layers of CdxHg1-xTe with low series resistance for purposes of hete
rodyne reception. Photodiodes with a long-wavelength photosensitivity limit
in the 8-12-mu m region are fabricated, and their parameters are studied.
The effect of the composition profile on the quantum efficiency is theoreti
cally calculated. (C) 1999 The Optical Society of America. [S1070-9762(99)0
1912-0].