Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

A key goal of metalens research is to achieve wavefront shaping of light using optical elements with thicknesses on the order of the wavelength. Such miniaturization is expected to lead to compact, nanoscale optical devices with applications in cameras, lighting, displays and wearable optics. However, retaining functionality while reducing device size has proven particularly challenging. For example, so far there has been no demonstration of broadband achromatic metalenses covering the entire visible spectrum. Here, we show that by judicious design of nanofins on a surface, it is possible to simultaneously control the phase, group delay and group delay dispersion of light, thereby achieving a transmissive achromatic metalens with large bandwidth. We demonstrate diffraction-limited achromatic focusing and achromatic imaging from 470 to 670 nm. Our metalens comprises only a single layer of nanostructures whose thickness is on the order of the wavelength, and does not involve spatial multiplexing or cascading. While this initial design (numerical aperture of 0.2) has an efficiency of about 20% at 500 nm, we discuss ways in which our approach may be further optimized to meet the demand of future applications. Controlling the geometry of each dielectric element of a nanostructured surface enables frequency-dependent group delay and group delay dispersion engineering, and the fabrication of an achromatic metalens for imaging in the visible in transmission.

/pdf/a-broadband-achromatic-metalens-for-focusing-and-imaging-in-1jmcuho99u.pdf

A broadband achromatic metalens for focusing and imaging in the visible.

Optical elements that convert the spin angular momentum (SAM) of light into vortex beams have found applications in classical and quantum optics. These elements—SAM-to–orbital angular momentum (OAM) converters—are based on the geometric phase and only permit the conversion of left- and right-circular polarizations (spin states) into states with opposite OAM. We present a method for converting arbitrary SAM states into total angular momentum states characterized by a superposition of independent OAM. We designed a metasurface that converts left- and right-circular polarizations into states with independent values of OAM and designed another device that performs this operation for elliptically polarized states. These results illustrate a general material-mediated connection between SAM and OAM of light and may find applications in producing complex structured light and in optical communication.

Arbitrary spin-to–orbital angular momentum conversion of light

BACKGROUND Future high-performance portable and wearable optical devices and systems with small footprints and low weights will require components with small form factors and enhanced functionality. Planar components based on diffractive optics (e.g., gratings, Fresnel lenses) and thin-film optics (e.g., dielectric filters, Bragg reflectors) have been around for decades; however, their limited functionality and difficulty of integration have been key incentives to search for better alternatives. Owing to its potential for vertical integration and marked design flexibility, metasurface-based flat optics provides a rare opportunity to overcome these challenges. The building blocks (BBs) of metasurfaces are subwavelength-spaced scatterers. By suitably adjusting their shape, size, position, and orientation with high spatial resolution, one can control the basic properties of light (phase, amplitude, polarization) and thus engineer its wavefront at will. This possibility greatly expands the frontiers of optical design by enabling multifunctional components with attendant reduction of thickness, size, and complexity. ADVANCES Recent progress in fabrication techniques and in the theory and design of metasurfaces holds promise for this new optical platform (metaoptics) to replace or complement conventional components in many applications. One major advance has been the migration to all-dielectric metasurfaces. Here, we discuss the key advantages of using dielectric phase-shifting elements with low optical loss and strong light confinement in the visible and near-infrared regions as BBs of flat lenses (metalenses). High–numerical aperture metalenses that are free of spherical aberrations have been implemented to achieve diffraction-limited focusing with subwavelength resolution, without requiring the complex shapes of aspherical lenses. Achromatic metalenses at discrete wavelengths and over a bandwidth have been realized by dispersion engineering of the phase shifters. By suitably adjusting the geometrical parameters of the latter, one can impart polarization- and wavelength-dependent phases to realize multifunctional metalenses with only one ultrathin layer. For example, polarization-sensitive flat lenses for chiral imaging and circular dichroism spectroscopy with high resolution have been realized, and off-axis metalenses with large engineered angular dispersion have been used to demonstrate miniature spectrometers. The fabrication of metalenses is straightforward and often requires one-step lithography, which can be based on high-throughput techniques such as deep-ultraviolet and nanoimprint lithography. OUTLOOK In the near future, the ability to fabricate metalenses and other metaoptical components with a planar process using the same lithographic tools for manufacturing integrated circuits (ICs) will have far-reaching implications. We envision that camera modules widely employed in cell phones, laptops, and myriad applications will become thinner and easier to optically align and package, with metalenses and the complementary metal-oxide semiconductor–compatible sensor manufactured by the same foundries. The unprecedented design freedom of metalenses and other metasurface optical components will greatly expand the range of applications of micro-optics and integrated optics. We foresee a rapidly increasing density of nanoscale optical elements on metasurface-based chips, with attendant marked increases in performance and number of functionalities. Such digital optics will probably follow a Moore-like law, similar to that governing the scaling of ICs, leading to a wide range of high-volume applications.

http://science.sciencemag.org/content/sci/358/6367/eaam8100.full.pdf

Metalenses: Versatile multifunctional photonic components

Optical metasurfaces have provided us with extraordinary ways to control light by spatially structuring materials. The space-time duality in Maxwell's equations suggests that additional structuring of metasurfaces in the time domain can even further expand their impact on the field of optics. Advances toward this goal critically rely on the development of new materials and nanostructures that exhibit very large and fast changes in their optical properties in response to external stimuli. New physics is also emerging as ultrafast tuning of metasurfaces is becoming possible, including wavelength shifts that emulate the Doppler effect, Lorentz nonreciprocity, time-reversed optical behavior, and negative refraction. The large-scale manufacturing of dynamic flat optics has the potential to revolutionize many emerging technologies that require active wavefront shaping with lightweight, compact, and power-efficient components.

https://science.sciencemag.org/content/sci/364/6441/eaat3100.full.pdf

Spatiotemporal light control with active metasurfaces

We present a method allowing for the imposition of two independent and arbitrary phase profiles on any pair of orthogonal states of polarization-linear, circular, or elliptical-relying only on simple, linearly birefringent wave plate elements arranged into metasurfaces. This stands in contrast to previous designs which could only address orthogonal linear, and to a limited extent, circular polarizations. Using this approach, we demonstrate chiral holograms characterized by fully independent far fields for each circular polarization and elliptical polarization beam splitters, both in the visible. This approach significantly expands the scope of metasurface polarization optics.

/pdf/metasurface-polarization-optics-independent-phase-control-of-3djyufb8ya.pdf

Metasurface Polarization Optics: Independent Phase Control of Arbitrary Orthogonal States of Polarization.

Recently, developments in meta-surfaces have allowed for the possibility of a fundamental shift in lens manufacturing—from the century-old grinding technology to nanofabrication—opening a way toward mass producible high-end meta-lenses. Inspired by early camera lenses and to overcome the aberrations of planar single-layered meta-lenses, we demonstrate a compact meta-lens doublet by patterning two metasurfaces on both sides of a substrate. This meta-lens doublet has a numerical aperture of 0.44, a focal length of 342.5 μm, and a field of view of 50° that enables diffraction-limited monochromatic imaging along the focal plane at a wavelength of 532 nm. The compact design has various imaging applications in microscopy, machine vision, and computer vision.

Meta-Lens Doublet in the Visible Region

Compact metasurface devices herald an exciting revolution in optics technology. Their design complexity and functionality has been restricted to intuitive by-hand designs for single-layered devices. This study proposes a large-scale approach known as topology optimization, applied to multiple, closely spaced device layers, which greatly expands the scope and functionality of metadevices. In particular, the authors demonstrate angular phase control, the ability to encode arbitrary information using different angles of incidence, which enables $e.g.$ the design of a one-piece, aberration-corrected metalens, and of an angle-convergent metalens.

Topology-Optimized Multilayered Metaoptics

A multi-layered lens comprises a plurality of metasurface layers. At least some layers of the plurality of metasurface layers include features that exhibit angular phase controls. The angular phases of the at least some layers cause an angular aberration correction or an angle convergence that focuses light onto a focal point regardless of angles of incidence.

Topology optimized multi-layered meta-optics

We present here a compact metasurface lens element that enables simultaneous and spatially separated imaging of light of opposite circular polarization states. The design overcomes a limitation of previous chiral lenses reliant on the traditional geometric phase approach by allowing for independent focusing of both circular polarizations without a 50% efficiency trade-off. We demonstrate circular polarization-dependent imaging at visible wavelengths with polarization contrast greater than 20dB and efficiencies as high as 70%.

/pdf/high-efficiency-chiral-meta-lens-4gb3310j1p.pdf

Benedikt Groever

Papers

Metasurface Polarization Optics: Independent Phase Control of Arbitrary Orthogonal States of Polarization.

Meta-Lens Doublet in the Visible Region

Topology-Optimized Multilayered Metaoptics

Topology optimized multi-layered meta-optics

High-efficiency chiral meta-lens