Multireflection modal method for wideband fused-silica transmission gratings

Abstract

A multireflection modal method is proposed to give a clear physical picture for explanation of the diffraction process that takes place in a wideband fused-silica transmission grating. Using rigorous coupled-wave analysis, the optimized grating exhibits diffraction efficiency greater than 93.9% for TE polarization over a bandwidth of 126 nm (from 735 to 861 nm). The designed wideband fused-silica transmission grating is fabricated using holographic interference recording and inductively coupled plasma etching technology. Experimental results are in agreement with the theoretical values.

Metagrating-Based Terahertz Polarization Beam Splitter Designed by Simplified Modal Method

“…The reflection at the grating/substrate interface is treated in the same way. The reflection and transmission coefficients of the mth propagation mode are given by: [41] where n si eff = n 1 cos ϕ n is the effective refractive index in silicon. Multireflection is not taken into account here in order to simplify the calculation.…”

Highly–efficient polarization–insensitive antireflection metagrating for terahertz waves

“…The whole grating design process based on the SMM is now basically reduced to solving the mode equation to obtain neff and then use standard Fresnel formula to calculate the transmittance and reflectance. The TE case can be treated in the same way by first solving the characteristic equation for the TE wave [29,30] and then using the above Fabry-Perot analysis. We use a commercial simulation software COMSOL to verify the feasibility of the SMM.…”

“…Clausnitzer et al proposed an intelligible explanation of deep-etched dielectric gratings and explained the physical processes happening in the grating [27][28][29] by considering the interference of only a few propagating modes inside the grating region. This simplified modal method (SMM) was further developed and applied to various device designs [30][31][32].…”

Optomechanics of a stable diffractive axicon light sail

“…The first experimental verification of this principle, along with the measurements of parametric damping, was reported by Chu [29,30]. Furthermore, advancements in the design and fabrication of diffractive films using metamaterial principles provide opportunities to engineer desired optomechanical and other properties into the functionality of a sail [31][32][33][34][35][36][37][38][39][40][41][42][43][44]. In the near term we envision the integration of diffractive light sail components on future solar sailing missions to help resolve engineering challenges [45] such as attitude control (see for example, Near-Earth Asteroid Scout [46], Solar Polar Imager [47], and Solar Cruiser [48]).…”