Experimental investigation of circular Bragg phenomenon exhibited by a mirror-backed chiral sculptured thin film

Abstract

Experimentation with obliquely incident light established that all four circular reflectances of a chiral sculptured thin film backed by a metallic mirror contain strong evidence of the circular Bragg phenomenon. When the mirror is removed, strong evidence of that phenomenon is found only in the spectrum of the co-polarized and co-handed reflectance.

Spin-to-Orbital Angular Momentum Mapping of Polychromatic Light

“…1(c) and discussed in Ref. [31]. Arbitrarily polarized light is thus fully Bragg reflected for optical frequencies inside the band gap; see Fig.…”

Alteration of optical Bragg phenomenon by substrate roughness

“…The plane-wave response characteristics of Bragg mirrors of both types were determined for λ 0 ∈ [500 nm, 900 nm] in a dark room, using a custom computer-controlled variable-angle spectroscopic system described elsewhere [5,11,15], λ 0 being the free-space wavelength. The specular linear reflectances R ss , R ps , R sp , and R pp of both films deposited on glass slides were measured for θ inc ∈ [10 • , 70 • ], in steps of 5 • , θ inc being the angle of incidence with respect to the z axis.…”

“…It must be sufficiently thick for its plane-wave reflectance to be extremely high in certain spectral regimes that depend on the direction of propagation and the polarization state of the incident plane wave. Although Bragg mirrors for lasers are commonly produced by physical vapor deposition of alternating layers of two different isotropic dielectric materials [1,2,3,4], Bragg mirrors can also be made of anisotropic thin films [5,6,7], cholesteric liquid-crystalline materials [8,9,10], and chiral sculptured thin films [11,12].…”

Experimental and theoretical investigation of the co-occurrence of linear and circular dichroisms for oblique incidence of light on chiral sculptured thin films

“…Theoretical results for oblique incidence have also been published [36][37][38][39][40][41][42], but experimental data for oblique incidence are rare and incomprehensive [36,[42][43][44][45][46][47]. Although spectrums of the circular reflectances and transmittances over wide ranges of both λ 0 and θ inc have recently been published [21,48], we provide calculated values of R L , R R , T L , and T R as functions of λ 0 and θ inc in Fig. 1 both for completeness as well as to contextualize novel results.…”