title: Necessary and sufficient conditions for the appearance of a reflectance minimum at oblique incidence when unpolarized or circularly polarized light is reflected at a dielectric-conductor interface.
abstract: The appearance of a reflectance minimum at oblique incidence when unpolarized or circularly polarized light is reflected at a dielectric-conductor interface requires that the normal-incidence intensity reflectance R(0) of the interface be >1/3 [J. Opt. Soc. A9, 957 (1992)10.1364/JOSAA.9.000957; Appl. Opt.53, 7885 (2014)APOPAI0003-693510.1364/AO.53.007885]. However, R(0) 1/3 is only a necessary but insufficient condition for the interface reflectance to exhibit a minimum at non-normal incidence. A second condition, the subject of this study, restricts the normal-incidence reflection phase shift δ(0) for s-polarized light to one of two non-overlapping bands: (a) 0≤δ(0)<δ(0 max) and (b) δ(0 min)<δ(0)≤180°. These two bands are associated with internal and external reflection, respectively. The limiting phase shifts δ(0 max) and δ(0 min) at the band edges are determined analytically as functions of R(0) .
authors.forename: R M A
authors.initials: RM
authors.lastname: Azzam