Abstract

The specular reflectance of the silicon photodiodes commonly used as radiometric standards in the self-calibration method has been studied as a function of time and cleaning procedure. The two types of photodiode studied were a group of inversion layer devices and a group of PN devices: UDT model UV100 and EG&G model UV444BQ, respectively. The reflectance loss is the largest correction factor that must be measured in the self-calibration of these devices. Consequently its variation will have the largest effect on the absolute responsivity. The measurements were performed at 482.5 nm near the region of maximum reflectance of the photodiode’s silicon dioxide antireflection coating.

© 1986 Optical Society of America