Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1608.04166

Large field enhancement obtained by combining Fabry-Perot resonance and Rayleigh anomaly in photonic crystal slabs

Kokou B. Dossou
View original source ↗Read source document ↗Export metadata ↓

Abstract

By applying the properties of Fabry-Perot resonance and Rayleigh anomaly, we have shown that a photonic crystal slab can scatter the light from an incident plane wave into a diffracted light with a very large reflection or transmission coefficient. The enhanced field is either a propagating diffraction order (with a grazing angle of diffraction) or a weakly evanescent order, so it can be particularly useful for applications requiring an enhanced propagating field (or an enhanced field with a low attenuation). An efficient effective medium technique is developed for the design of the resonant photonic crystal slabs. Numerical simulations have shown that photonic crystal slabs with low index contrast, such as the ones found in the cell wall of diatoms, can enhance the intensity of the incident light by four orders of magnitude.

Explore related subjects

physics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kokou B. Dossou. 2017-03-22. Large field enhancement obtained by combining Fabry-Perot resonance and Rayleigh anomaly in photonic crystal slabs. https://doi.org/10.1088/2040-8986%2Faa608b

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Vectorial Control of Scintillation in Kolmogorov Turbulence and Quality Parametrization

Intensity scintillation limits free-space optical links in strong turbulence. We examine experimentally how sequential linear polarization filtering modifies the scintillation of a laser beam distorted by Kolmogorov-type turbulence, and interpret the results with a vector-field and fourth-order-moment model. A collimated He--Ne beam (632.8~nm) crossed a rotating pseudo-random phase plate (Fried parameter $r_0\approx0.6$~mm) and zero to five co-aligned thin-film polarizers; 200 camera frames were recorded per configuration, together with a turbulence-free reference. For fully developed speckle the model gives a total-field index $σ_I^2=(1+P^2)/2$ in terms of the degree of polarization $P$. From zero to five polarizers, the Gaussian-envelope scintillation index fell from 0.083 to 0.002 and the single-pixel index from 0.80 to 0.27 (about 66\%), whereas beam wander remained comparable across configurations. As Gaussian statistics alone cannot explain this reduction, we attribute it to rejection of a depolarized, strongly fluctuating component and derive a quantitative criterion for this mechanism. Passive polarization filtering thus offers a simple, low-cost route to scintillation mitigation in free-space optical terminals.

physics.optics↗
arXiv2026

Constraints on the Origin of Universal $1/f^2$ Photon-Count Spectra at Baseband

A series of 11.6-d-duration photon-counting experiments, employing a broad variety of light sources with different statistical properties and optical spectra, were carried out over a 1.5-yr period. All of the photon-count spectra at baseband followed a common $1/f^2$ form over the frequency range $1 \times 10^{-6} \leqslant f \leqslant 5 \times 10^{-4}$ Hz, corresponding to a timescale range $33$ min $ \leqslant T_f \leqslant 11.6$ d, where $T_f \equiv 1/f$. The lower and upper timescale limits were established by the photodetector noise floor and the duration of the individual experiments, respectively. Unlike ordinary Brownian motion, all of the measured photon-count sample paths exhibited irregular long-timescale fluctuations, with durations ranging from hours to days. It has been established that the photon-count spectra cannot plausibly be ascribed to fluctuations of the current, voltage, or temperature of the source or the detector, nor to technical sources of noise associated with the optical system or local environment. Although the physical origin of the photon-count fluctuations remains unresolved, several heterodox hypotheses are set forth. From a statistical point-of-view, the photon counts appear to follow a doubly stochastic Poisson process with a slowly varying random intensity. Analogous experiments that rely on ionizing radiation and direct-conversion solid-state radiation detectors are proposed.

physics.optics↗
arXiv2026

Scatter-free perfect reflection in multichannel monolithic high-contrast gratings: direct--indirect Fourier-harmonic interference and dimensionality of the solution set

Monolithic high-contrast gratings (MHCGs) can exhibit scatter-free perfect reflection despite open higher-order substrate diffraction channels, but the underlying mechanism has not been fully clarified. Using a Fourier-harmonic description, we show that all open higher-order channels in the high-index substrate can be simultaneously extinguished through destructive interference between the radiation fields generated by the direct and indirect source contributions. By contrast, the zeroth-order transmission vanishes when the modulation-induced zeroth-order field interferes destructively with the background transmitted field of the incident wave. Together, these cancellations yield unit zeroth-order reflectance in lossless MHCGs. The near invariance of the internal field harmonics accounts for the remarkable stability of these conditions against changes in the substrate refractive index. We further show that the number of symmetry-compatible open channels determines the generic codimension of the perfect-reflection solution set. Depending on the number of independent design parameters relative to this codimension, the solutions form continuous curves, appear as isolated points, or are generically absent. Introducing an additional geometrical parameter restores isolated perfect-reflection solutions when an additional diffraction channel opens. The same cancellation mechanisms and channel counting apply to both TE and TM polarizations.

physics.optics↗