Geometric limits to geometric optical imaging with infinite, planar, non-absorbing sheets

A planar Airy beam light-sheet for two-photon microscopy

We demonstrate the first planar Airy light-sheet microscope. Fluorescence light-sheet microscopy has become the method of choice to study large biological samples with cellular or sub-cellular resolution. The propagation-invariant Airy beam enables a ten-fold increase in field-of-view with single-photon excitation; however, the characteristic asymmetry of the light-sheet limits its potential for multi-photon excitation. Here we show how a planar light-sheet can be formed from the curved propagation-invariant Airy beam. The resulting symmetric light sheet excites two-photon fluorescence uniform…

Perfect imaging with planar interfaces

We describe the most general homogenous, planar, light-ray-direction-changing sheet that performs one-to-one imaging between object space and image space. This is a non-trivial special case (of the sheet being homogenous) of an earlier result [J. Courtial, Opt. Commun.282, 2480 (2009)]. Such a sheet can be realised, approximately, with generalised confocal lenslet arrays.

Analytical Investigation of Magneto-Plasmons in Anisotropic Multi-layer Planar Waveguides Incorporating Magnetically Biased Graphene Sheets

This article proposes a novel analytical model for the anisotropic multi-layer structures containing magnetically biased graphene sheets. The multi-layer structure is composed of various magnetic materials. An external magnetic field is applied, normal to the structure surface. Each graphene sheet, with an anisotropic conductivity tensor, has been sandwiched between two adjacent magnetic materials. Our model is used to find the dispersion relation of the structure. Now, obtaining plasmonic features of the structure, such as the effective index and propagation loss is straightforward. Four exem…

Designing Planar, Ultra-Thin, Broad-Band and Material-Versatile Solar Absorbers via Bound-Electron and Exciton Absorption

Ultrathin planar absorbing layers, including semiconductor and metal films, and 2D materials, are promising building blocks for solar energy harvesting devices but poor light absorption has been a critical issue. Although interference in ultrathin absorbing layers has been studied to realize near perfect absorption at a specific wavelength, achieving high broadband absorption still remains challenging. Here, we both theoretically and experimentally demonstrated a method to tune not only reflection phase shift but also electromagnetic energy dissipation to design broadband solar absorber with s…

双平面极化激元共振结构的近场增强和成像

Near-field enhancement and imaging in double planar polariton-resonant structures

结果表明，具有表面模式（极化激元）共振的两个耦合的平面材料片的系统可以用于倏逝场恢复的目的，因此，用于亚波长近场成像。将板放置在自由空间中，使它们平行并分开一定距离。由于片的谐振表面模式（极化激元）的相互作用，可以实现通过系统的渐逝平面波的振幅的指数增长。这种效应以前曾被预测为后向波（双负或Veselago）平板透镜。这里考虑的替代系统被证明是可实现的，在微波的网格或阵列的共振粒子。共振网格和粒子的必要的电磁特性的研究和建立。理论结果得到了微波实验的支持，证明放大的倏逝模。

Absorbing photonic crystals for thin film photovoltaics

The absorption of thin hydrogenated amorphous silicon layers can be efficiently enhanced through a controlled periodic patterning. Light is trapped through coupling with photonic Bloch modes of the periodic structures, which act as an absorbing planar photonic crystal. We theoretically demonstrate this absorption enhancement through one or two dimensional patterning, and show the experimental feasibility through large area holographic patterning. Numerical simulations show over 50% absorption enhancement over the part of the solar spectrum comprised between 380 and 750nm. It is experimentally …