Experimental demonstration of ultrasharp unpolarized filtering by resonant gratings at oblique incidence

Abstract

The peaks in the reflectivity spectrum of waveguide gratings observed when the incident beam couples to a mode of the structure are promising features for many applications. However their weak angular tolerance and their strong polarization sensitivity, especially under oblique incidence, limit their interest in practice. These problems can be overcome by forming slow degenerate modes outside the usual high symmetry points of the Brillouin zone with a complex periodic pattern [Fehrembach, Appl. Phys. Lett. 86, 121105 (2005)]. We show experimentally that spectrally sharp, lambda/Deltalambda approximately 4000, polarization-independent, angularly tolerant optical resonances can be obtained by exciting these modes under oblique incidence.

Analysis of light scattering off photonic crystal slabs in terms of Feshbach resonances

“…The magnetic fields H ± 0 (z) and the Green's function g H 0 (z, z ) satisfy the homogeneous and inhomogeneous differential equation (5) respectively with D 00 given by Eq. (16). The same boundary conditions for H ± 0 (z) are imposed as for E ± 0 (z) (Eq.…”

“…where w H (z) is the Wronskian given by the same formula as ( 7) with E ± 0 replaced by H ± 0 . The factor −γ 0 (z) is due to the presence of the first order derivative in the differential operator D 00 (16). It makes the denominator z-independent as is most easily shown by applying Abel's formula (cf.…”

“…Refs. [9][10][11][12][13][14][15][16][17][18]. In most theoretical investigations of these resonances [19][20][21][22] parameter fitting is required for comparison with data or exact numerical calculations [23,24].…”

Free-standing guided-mode resonance band-pass filters: from 1D to 2D structures

“…In the case of mid-or far-infrared imaging with extremely low photon flux, the 50% of incident light lost by reflection on polarizing filters is a strong drawback. Several studies have been dedicated to the design of polarization independent filters at normal [14][15][16] and oblique incidences [17][18][19][20].…”

Applications of sub-wavelength grating mirrors in high-power lasers

“…The sub-wavelength structures can be defined in one or more layers of the optical waveguide. In the past 30 years, the work of several scientific groups [1 -3] led to a deep phenomenological and theoretical understanding of the physical behavior of these structures with many applications in different fields such as telecommunications [6] , biology [7,8] , and lasers [9] .…”