Nonlinear Optics in Dielectric Guided-Mode Resonant Structures and Resonant Metasurfaces

Abstract

Nonlinear optics is an important area of photonics research for realizing active optical functionalities such as light emission, frequency conversion, and ultrafast optical switching for applications in optical communication, material processing, precision measurements, spectroscopic sensing and label-free biological imaging. An emerging topic in nonlinear optics research is to realize high efficiency optical functionalities in ultra-small, sub-wavelength length scale structures by leveraging interesting optical resonances in surface relief metasurfaces. Such artificial surfaces can be engineered to support high quality factor resonances for enhanced nonlinear optical interaction by leveraging interesting physical mechanisms. The aim of this review article is to give an overview of the emerging field of nonlinear optics in dielectric based sub-wavelength periodic structures to realize efficient harmonic generators, wavelength mixers, optical switches etc. Dielectric metasurfaces support the realization of high quality-factor resonances with electric field concentrated either inside or in the vicinity of the dielectric media, while at the same time operate at high optical intensities without damage. The periodic dielectric structures considered here are broadly classified into guided-mode resonant structures and resonant metasurfaces. The basic physical mechanisms behind guided-mode resonances, electromagnetically-induced transparency like resonances and bound-states in continuum resonances in periodic photonic structures are discussed. Various nonlinear optical processes studied in such structures with example implementations are also reviewed. Finally, some future directions of interest in terms of realizing large-area metasurfaces, techniques for enhancing the efficiency of the nonlinear processes, heterogenous integration, and extension to non-conventional wavelength ranges in the ultra-violet and infrared region are discussed.

Numerical Analysis of the Light Modulation by the Frustule of Gomphonema parvulum: The Role of Integrated Optical Components

“…For a specific range of wavelengths, the grid-like element exhibits another phenomenon, guided-mode resonance (GMR), which is widely reported for dielectric resonant gratings and photonic crystals of period d comparable to λ vacc [ 89 , 90 , 91 ]. At a specific combination of various parameters related to the incident light, including λ vacc , ϴ inc , and polarization, and the grid, including thickness D , pore spacing d , filling factor ff , and its material refractive index n , the grid-coupled GMR can be obtained [ 90 , 92 , 93 , 94 ].…”

An Introduction to Nonlinear Integrated Photonics: Structures and Devices

“…There is strong interest in exploring interesting physical mechanisms to create the optical resonances in such structures, for example, using guided-mode resonances [ 99 ] and bound-states in continuum resonances [ 100 ], to enhance local electric fields and consequently amplify the nonlinear optical effects in metamaterials [ 12 , 101 , 102 , 103 , 104 , 105 ]. Bound states in the continuum (BIC), experimentally observed by Capasso et al in semiconductor heterostructures grown by molecular-beam epitaxy [ 106 ] in 1992, are special wave solutions embedded in a radiative continuum, which, however, remain localized without coupling to the extended waves or radiation.…”

Diffractive Nonlocal Metasurfaces

“…This dispersion is governed by the band structure of the infinite, periodic device, whose period is commonly subwavelength (a so-called "0th order grating") in order to guarantee complete interference and unity reflectance in the absence of loss, [68] and resulting in a response limited to specular reflection and transmission [see Figure 1b]. Such nondiffractive nonlocal devices can operate as bandpass filters, [69][70][71] refractive index sensors, [72][73][74][75] nonlinear optical elements, [76][77][78][79] active photonic elements, [80,81] and image differentiators. [82][83][84][85] In the general case, a nonlocal mode whose coupling to external waves is spatially customizable can combine both the spatial control typical of local metasurfaces [Figure 1a] and the frequency selectivity of nonlocal metasurfaces [Figure 1b].…”

“…This dispersion is governed by the band structure of the infinite, periodic device, whose period is commonly subwavelength (a so‐called “0th order grating”) in order to guarantee complete interference and unity reflectance in the absence of loss, [ 68 ] and resulting in a response limited to specular reflection and transmission [see Figure 1b]. Such nondiffractive nonlocal devices can operate as bandpass filters, [ 69–71 ] refractive index sensors, [ 72–75 ] nonlinear optical elements, [ 76–79 ] active photonic elements, [ 80,81 ] and image differentiators. [ 82–85 ]…”