Gradient Nonlinear Pancharatnam-Berry Metasurfaces

Abstract

We apply the Pancharatnam-Berry phase approach to plasmonic metasurfaces loaded by highly nonlinear multi-quantum well substrates, establishing a platform to control the nonlinear wavefront at will based on giant localized nonlinear effects. We apply this approach to design flat nonlinear metasurfaces for efficient second-harmonic radiation, including beam steering, focusing, and polarization manipulation. Our findings open a new direction for nonlinear optics, in which phase matching issues are relaxed, and an unprecedented level of local wavefront control is achieved over thin devices with giant nonlinear responses.Artificially engineered metasurfaces have recently attracted a great deal of interest due to their ability to provide a large degree of control over the local amplitude, phase, and polarization of local fields, leading to many exciting advances in science and technology [1,2]. Conventional optical devices are based on the naturally weak interactions of light with matter, implying that volumetric effects dominate their optical response. Metasurfaces provide an elegant way to overcome these constraints, by manipulating the local field with suitably engineered inclusions that can enhance the local interaction with light, and pattern it in the desired way over

Multiwavelength polarization-insensitive lenses based on dielectric metasurfaces with meta-molecules

“…For instance, it can be used to implement a lens with two given focal distances at two wavelengths, or a lens converging at one wavelength and diverging at the other. In addition, given the generality of the meta-molecule concept, it can be applied to other areas of interest in metasurfaces (such as nonlinear [35][36][37] and microwave [38,39] metasurfaces). Multiwavelength operation is necessary in various microscopy applications where fluorescence is excited at one wavelength and collected at another.…”

Advanced control of nonlinear beams with Pancharatnam-Berry metasurfaces

“…In addition, ultrathin metasurfaces significantly alleviate phase matching constraints, which are of critical importance for efficient nonlinear processes [1,8]. Several attempts have been recently pursued to apply phase control techniques, which have been originally developed in linear optics, to nonlinear systems, aiming to provide a much-needed control over generated fields at subwavelength scales [3,4,[9][10][11]. Such nonlinear systems with wavefront engineering capabilities are paving the way towards a new paradigm in nonlinear optics, based on which advanced functionalities such as pencil beam steering, focusing, generation of vortex beams, holographic imaging, etc., are realized using ultrathin nonlinear metasurfaces, eliminating the need for bulky optical lenses and filters and mitigating the challenges associated with phasematching.…”

Plasmonic and Dielectric Metasurfaces: Design, Fabrication and Applications

“…Nanoimprint lithography is a more promising technique for combining many advantages of the former, such as high-resolution, large-scaled production and low processing cost [73]. The unique properties and the development of fabrication techniques have allowed metasurfaces to be applied in various fields, such as flat optics [33][34][35], nonlinear effects [101][102][103][104][105][106][107], photonic Hall effects [108][109][110], electromagnetically-induced transparency [111], cloaking [112][113][114][115][116][117], etc., as shown in Figure 2. For instance, the applications of metasurfaces in the field of flat optics mainly include anomalous reflection/refraction [34,81,82], wave plates [79,80], flats lens/axicons [83][84][85], mirrors [88], hologram [90][91][92][93][94][95], filters [96], optical vortex generation [34,85,98,99], polarization beam splitter [100], etc.…”

“…For instance, the applications of metasurfaces in the field of flat optics mainly include anomalous reflection/refraction [34,81,82], wave plates [79,80], flats lens/axicons [83][84][85], mirrors [88], hologram [90][91][92][93][94][95], filters [96], optical vortex generation [34,85,98,99], polarization beam splitter [100], etc. The applications of metasurfaces in the field of nonlinear effects mainly include second/third harmonic generation [102][103][104][105] and enhanced absorbing [106,107].…”