Radiometry and radiation efficiency of twisted Gaussian Schell-model sources

Wavefields endowed with the coherence-induced property of optical twist hav e recently attracted a good deal of theoretical and experimental attention. We present the generalized radiometric theory of fields generated by twist ed Gaussian Schell-model sources. The effects introduced by the novel, rota tionally symmetric, twist phenomenon in the radiant intensity, generalized radiance, radiant emittance (irradiance), and the radiation efficiency are assessed. The radiance becomes directionally skewed as a result of the twis t, whereas the radiant intensity remains axially symmetric. The twist reduc es the radiation efficiency and broadens the radiation distribution, in agr eement with the notion that the twist decreases the effective coherence. Se veral special cases, such as quasihomogeneous sources, are analyzed in deta il. The radiometric results, which are physically consistent with the super position models of twisted sources, are demonstrated by illustrative exampl es.