Abstract

Attempts to elucidate the foundation of radiometry have up to now met with limited success. It was found, for example, that although many different functions exhibiting some of the properties of the radiance may be defined within the framework of second-order correlation theory of statistical wavefields, none of them satisfies all the basic postulates of radiometry.¹ We show that the various definitions are different phase-space representations of the cross-spectral density.² The particular form depends on the choice of a mapping function from configuration space to phase space.³ We also show that, in the short-wavelength limit, different generalized radiance functions of a quasi-homogeneous source reduce to the same quantity, recently discussed elsewhere,⁴ which may be identified with the radiance of traditional radiometry.

© 1986 Optical Society of America