Information-Efficient Metagrating for Transverse-Position Metrology

Abstract

We introduce an optimal metagrating design for transverse-position metrology in presence of photon shot noise. The proposed working principle is closely related to the formation of a phase vortex in the diffraction orders in the parameter space. Using the topological robustness, we optimize the design and compress all the transverse-position information around a certain point into a small number of detected photons, saturating the shot-noise limit had all the photons used for probing the position been detected. The current scheme avoids the problem of detector saturation in the presence of high probe power while maintaining all the information detected, allowing one to make full use of the high power that is available. Besides, the direct link between the resonant property in the unit cell and the conditions to achieve the bound is given: one with the zeroth dipole resonance and the other one with the anapole condition of the first dipole. The connection between the metagrating design and the optimization using topological robustness along with the fundamental precision limit using classical light gives new insights in all of these fields.

Metagratings for Efficient Wavefront Manipulation

“…However, just to give the readers a flavor of the broad scope of research areas that have employed this concept, here we list a few of the main applications that have been introduced in the past few years. Metagratings have been employed for lensing [52], [65], [85]- [87], holograms [88], [89], generation of vortex beams [90], [91], sensors [92], [93], high-Q resonators [94], ultra-narrowband absorbers [95], [96], power splitters [97]- [99], spectrum splitters [100], optical computing [101], [102], engineering reactive near field profiles [103], waveguiding for mode conversion and elimination of reflections at the bends [104], [105], light emitting devices [106], metrology [107], photovoltaics [108], retroreflectors [109], space-to-surface wave converting surfaces [110], and waterborne acoustics [79].…”

Simultaneously detecting transversal and longitudinal displacement with the dielectric metasurface

“…The recent progress of nano-optics makes it feasible to develop a compact displacement sensor with accuracy down to the subnanometer. Several compact devices [5][6][7][8][9][10] have been proposed for transversal position sensing, such as collecting highly positiondependent directional scattering from an optical antenna [5,6] , utilizing modulated structure light interference [7] , and employing super-oscillatory fields [8] . Recently, a polarization-encoded metasurface was used to realize one-dimensional lateral displacement measurement with subnanometric resolution over an enormous range [11,12] , providing a new avenue for using the metasurface for displacement sensing.…”

Ultrasensitive and long-range transverse displacement metrology with polarization-encoded metasurface

“…Recently, there is a growing interest in the field of nanophotonics to develop novel compact devices other than large-scale interferometers for transverse position sensing (6)(7)(8)(9)(10)(11)(12), which is especially important for applications in semiconductor industry and super-resolution microscopy where the room for placing the displacement sensor is rather limited. For instance, using the highly position-dependent directional scattering from an optical antenna placed inside a spatially tailored focused field, a localization precision on the order of subangstrom has been demonstrated (8,11).…”