Experimental realization of a high-contrast grating based broadband quarter-wave plate

Abstract

Fabrication and experimental characterization of a broadband quarter-wave plate, which is based on two-dimensional and binary silicon high-contrast gratings, are reported. The quarter-wave plate feature is achieved by the utilization of a regime, in which the proposed grating structure exhibits nearly total and approximately equal transmission of transverse electric and transverse magnetic waves with a phase difference of approximately π/2. The numerical and experimental results suggest a percent bandwidth of 42% and 33%, respectively, if the operation regime is defined as the range for which the conversion efficiency is higher than 0.9. A compact circular polarizer can be implemented by combining the grating with a linear polarizer.

A review of dielectric optical metasurfaces for wavefront control

“…More recently, metallic and dielectric metasurfaces have been widely used to control the polarization of light [13,17,33,39,42,44,46,70,[142][143][144][145][146][147][148][149][150][151][152][153][154][155][156]. Many of these devices are uniform waveplates that simply transform the polarization of the input wave upon reflection or transmission [39,142,143,[146][147][148][149][150]. Many of the other designs are based on polarization dependent scatterers that locally act as waveplates (usually half-waveplates), but have varying rotations across the metasurface [17,33,42,44,46,52,70,145,[151][152][153][154][155][156].…”

“…Therefore, any desired phase profile can be encoded into a metasurface to provide a specific functionality. Lenses [6,52,66,67,72,117,123,206,207], focusing mirrors [32,48,119,180,208,209], collimators [68,210], waveplates [17,33,42,44,46,52,142,145], beam deflectors (gratings) [35,78,127,128,131,[211][212][213][214], spiral phase plates [13,66,118,160,[215][216][217], orbital angular momentum (OAM) generators [45,196,[218][219][220][221][222], and holograms …”

Dielectric metasurfaces for complete control of phase and polarization with subwavelength spatial resolution and high transmission

“…Components based on 1D high contrast gratings have higher efficiencies, but do not provide high spatial resolution for realizing precise phase or polarization profiles in the direction along the grating lines [4,[11][12][13][14]. The majority of flat elements have been realized using a platform that provides only phase control [3,4,6,11,13,[15][16][17][18][19][20] (in most cases only for a fixed input polarization), or only a limited polarization modification capability [5,[21][22][23][24][25]. The platform we propose does not suffer from these limitations and provides a unified framework for realizing any device for polarization and phase control with an average transmission higher than 85%.…”

Single-layer Linear-to-Circular Polarization Transformer Based on Periodic Strips Array

“…Researchers has recommended that avoid to use heavy waveguide walls and use two dimensional grating to design circular polarizer [17,18]. The polarization control is achieved by reflected waves for reflective metasurface [19].…”