Abstract

The question of whether a photodetector responds to the incident light intensity, the incident energy flux, or some other quantity has been de bated from time to time and has also been examined experimentally. We report on new measurements made with a photoemissive vacuum photodiode, in which the photocurrent produced by an incident laser beam was measured as a function of the angle of incidence, so that total internal reflection occurs at the photocathode. It is found that for an incident TE polarized beam the photoelectric current is proportional to the difference between the incident and reflected intensities or energy fluxes but not for an incident TM polarized beam. It, therefore, appears that the detector measures neither intensity nor energy flux for TM polarized light.

© 1987 Optical Society of America