Surface Of One-dimensional Photonic Crystal Research Articles

Bloch Surface Waves in Resonant Structures

In this work, we make a step forward in the manipulation of light on the surface of one-dimensional photonic crystal through Bloch Surface Waves (BSW) within resonant structures of various types. Linear Fabry-Perot cavities eventually combined with diffraction gratings allow to directly couple BSW from free-space radiation. Design, fabrication and experimental characterization are provided.

Directional luminescence of the diamond NV center via Bloch surface waves in one-dimensional photonic crystals

In this work, we numerically study the luminescence of nanodiamonds with NV centres embedded in a polymer layer on the surface of one-dimensional photonic crystal. The interaction of NV center spontaneous emission with the Bloch surface wave (BSW) is demonstrated. The presence of a photonic crystal leads to a change in the angular distribution of the emitter radiation due to the coupling of luminescence to BSW. We show that the best coupling efficiency of 71% is observed when NV centres are located in the close proximity to the BSW field maximum.

Photonic Spin Hall Effect Modified by Ultrathin Au Films and Monolayer Transition Metal Dichalcogenides in One-Dimensional Photonic Crystal

When the metal film becomes far thinner than the electron mean free path (EMFP) in their bulk counterpart, many exotic optical properties accompanied with numbers of novel applications may emerge. Herein, the photonic spin Hall effect (PSHE) occurring on the surface of one-dimensional photonic crystal consisting of ultrathin Au films, monolayer transition metal dichalcogenides (TMDCs), and one defective layer is investigated. The Au film thickness ranges from 2.4 to 40 nm which covers the thickness range below the EMFP (37.7 nm) in bulk Au. Results show that ultrathin Au films are more competent to enhance the PSHE than bulk Au film. In particular, the maximum spin-dependent transverse displacement (37.94 times of the incident wavelength) at the Au film thickness of 4.4 nm is more than 12-fold higher than that at the bulk Au film with thickness of 40 nm. Besides it may be due to the coupling between the short-range surface plasmon polaritons and the B excitonic resonance in monolayer WS2, among four monolayer TMDCs (i.e., MoS2, MoSe2, WS2, WSe2), the photonic crystal with monolayer WS2 gives the strongest PSHE. Additionally, evolutions of photonic spin Hall shifts with the refractive index of defective layer, incident wavelength, and incident angle are also studied in detail. These findings shed light on the superiority of ultrathin metal films for light manipulation in spinoptics and may provide new routes to tailor the optical helicity in nanophotonic devices.

Miniature Otto configuration implemented by two-photon laser lithography

In this work we develop the concept of miniature Otto configuration. The distinctive feature of the proposed prism configuration is an operation for normal angle of incidence. Polymer microprisms with size of several tens of microns were fabricated by two-photon laser lithography on a surface of one-dimensional photonic crystal. The performance of the prisms was studied in the case of the Bloch surface waves excitation. Design of the prism and its optimal geometrical parameters were obtained from results of calculations. Bloch surface waves excitation with the microprisms was observed by the leakage radiation microscopy. The dependence of coupling efficiency on the angle of incidence was studied. Proposed prism configuration is easily compatible with fibers and is very appealing alternative to diffraction grating coupling for future applications.

Optical properties of mesoporous one-dimensional photonic crystals

The systematic features in the reflectance spectra of broadband optical radiation from the surface of one-dimensional photonic crystals based on mesoporous structures are presented. The dispersion dependence for electromagnetic waves in the mesoporous one-dimensional photonic crystal is established. On its basis, reflectance and transmittance spectra are calculated for particular structures, and the microscopic parameters of the samples under study are determined. The developed theory is used to explain the shape of reflectance spectra in mesoporous photonic crystals based on silicon, quartz, and aluminum oxide.

Long-range surface plasmon amplification with current injection on a one-dimensional photonic crystal surface.

A one-dimensional (1D) semiconductor photonic crystal (PC) structure with a terminal metal nanofilm, supporting propagation of long-range surface plasmons (LRSPs), is considered as an LRSP amplifier with current pumping. Current is injected to an active region through the metal nanofilm from one side and doped semiconductor layers from the other side. The propagation length of LRSP waves in such 1D PC structures reaches several millimeters, and therefore, a gain as low as 10 cm(-1) is enough to compensate for attenuation and amplify LRSPs. A unique advantage of this structure is that the refractive index of LRSP wave is very close to unity. As a result, no return reflection to semiconductor occurs during the edge-emission of LRSP to air, and this enhances the light extraction efficiency from semiconductor light sources such as edge-emitting superluminescent diodes and light-emitting diodes (LEDs). Optical feedback may be incorporated in this LRSP amplifier by grating deposition on the external side of the metal nanofilm, and LRSP lasing (i.e., long-range SPASER) may be realized without the use of complicated "etch-and-regrow" processes.

Fluorescence emission enhanced by surface electromagnetic waves on one-dimensional photonic crystals

An appreciable increase in the fluorescence emission of an organic chromofore is obtained by exploiting the local field enhancement at the surface of one-dimensional photonic crystals after excitation of surface electromagnetic waves (SEW). Using a properly designed photonic crystal consisting of alternating a-Si1−xNx:H layers with different nitrogen content, efficient emission of R6G dye spun on the surface of the photonic crystal is detected and the intensity spatial distribution of the SEW is visualized by means of far-field fluorescence microscopy. Our results demonstrate potential applications in enhanced fluorescence microscopy with an increased sensitivity and spectral selectivity.

Gap modes of one-dimensional photonic crystal surface waves

The finite-difference time-domain method is employed for the analysis of coupling of the surface modes of two truncated one-dimensional photonic crystals separated by a gap. The wave vector, field distributions, and existence conditions of the coupled surface modes are investigated. The wave vector of symmetric gap modes increases with decreasing gap width, while that of antisymmetric modes decreases-exactly opposite of the situation for surface plasmons on metallic half-spaces separated by a dielectric gap. Photonic crystal gap modes could easily and effectively be used as nondissipating gap-mode waveguides.