A method for measuring a refractive index of a medium includes exciting a first antisymmetric resonance of a first metasurface, including a first periodic array of resonators formed on a substrate surface, with illumination incident on the first metasurface at a non-normal incidence angle with respect to the substrate surface, the first metasurface including the medium encapsulating the first periodic array of resonators. The method also includes determining a refractive index of the medium from a first amplitude of a first transmitted signal that includes a portion of the illumination transmitted through the first metasurface.

The disclosed subject matter provides systems and methods for spatial and spectral modulation of light. An example system for modulating light can include a substrate and a plurality of meta units, coupled to the substrate and configured to spatially and spectrally modulate the light, wherein the plurality of meta units includes a perturbation and forms a perturbed lattice supporting a quasi-bound state in the continuum.

Methods of making a multilayer optical film are described. In one embodiment, the method comprises providing a multilayer optical film and disposing onto the multilayer optical film a plurality of layers deposited by layer-by-layer self-assembly of nanoparticles, polymers, and combinations thereof. The multilayer optical film typically comprises a plurality of alternating polymeric layers of a low refractive index layer and a high refractive index layer that reflects at least one bandwidth of electromagnetic radiation ranging from ultraviolet to near infrared. Multilayer optical film articles are described comprising a plurality of layers disposed onto the multilayer optical film, wherein the plurality of layers comprises layer-by-layer self-assembled nanoparticles, polymers, and combinations thereof. The multilayer optical films are suitable for various uses including reflective polarizers for optical displays such as LCDs or LEDs, architectural film applications, window film applications, and solar power concentrating mirrors.

A light-emitting device assembly includes an emitter array of light-emitting elements, a transparent substrate, a structured lens, and an angular filter. The emitter array emits from its emission surface output light that is transmitted through the substrate, and enables selective activation of and emission from individual elements or subsets of elements of the array. The structured lens is formed on or in the substrate, and comprises micro- or nano-structured elements resulting in an effective focal length less than an effective distance between the structured lens and the emission surface. The angular filter is positioned on or in the substrate or on the emission surface and exhibits decreasing transmission or a cutoff angle with increasing angle of incidence.

A photoelectric conversion device including a photoelectric converter, a transparent cover, an insulating material layer and a photonic crystal layer is provided. The photoelectric converter is adapted to receive a light. The transparent cover is disposed on a side of the photoelectric converter. The insulating material layer is disposed between the photoelectric converter and the transparent cover. The photonic crystal layer is disposed between the insulating material layer and the transparent cover, wherein the material of the photonic crystal layer is different from the material of the insulating material layer.

The present disclosure relates to a holographic display device and an electronic device. The holographic display device may include a light source, a light transmission structure, a first photonic crystal group, and a spatial light modulator. The light transmission structure has a light incident surface and a light exiting surface. The first photonic crystal group is disposed between the light incident surface and the light source. The first photonic crystal group includes various photonic crystals for dividing light emitted by the light source into light beams of different colors. The light beams of different colors are transmitted into the light transmission structure through the light incident surface and emitted through the light exiting surface. The spatial light modulator corresponds to the light exiting surface for modulating light beams of different colors emitted from the light exiting surface to form a holographic image.

A meta-crystal slab includes photonic structure with an input surface and an output surface, and a plurality of first voxels with a first permittivity and a plurality of second voxels with a second permittivity not equal to the first permittivity disposed between the input surface and the output surface. The photonic structure has a periodicity greater than an operating photonic wavelength ‘λ’ for general convolution by the photonic structure and the photonic structure is configured to provide an output image with a convolution of an input image.

A photonic resonator analyzer characterizes a photonic resonator and incudes a light source that provides a probe light; a photonic resonator that receives the probe light and produces product light; an optical detector that receives the product light and produces a product signal; a mode analyzer that receives the product signal and produces a resonator spectrum; and a spectral analyzer that receives the resonator spectrum, performs regression by fitting a non-parametric model to the resonator spectrum, and produces a thermal response function of the photonic resonator from fitting the non-parametric model to the resonator spectrum to characterize the photonic resonator.

Provided are an acousto-optic element, an acousto-optic element array, and a display apparatus including the acousto-optic element array. The acousto-optic element includes: an acousto-optic modulator which includes an acousto-optic layer formed of an acousto-optic material; a light supplier which supplies light to the acousto-optic modulator in a first direction; a first sound-wave modulator which applies first elastic waves to the acousto-optic modulator in a second direction; and a second sound-wave modulator which applies second elastic waves to the acousto-optic modulator in a third direction. The light supplied from the light supplier to the acousto-optic modulator is deflected by diffraction caused by the first elastic waves applied from the first sound-wave modulator and diffraction caused by the second elastic waves applied from the second sound-wave modulator, and is output from the acousto-optic modulator through a front side of the acousto-optic modulator.

A direction-selective interferometric optical filter for spectrometric devices, at least includes an arrangement of two layered one-dimensional photonic structures. Each of the two structures contains a defect layer, and each photonic structure has a dispersion function in the energy momentum space (E, kx, ky), wherein kx and ky are momentum components of transmitted photons of the photonic structures for a defined energy (frequency/wavelength) E in the energy momentum space. Both photonic structures have opposite interfaces which are at a plane-parallel distance from one another. In this case, the dispersion functions of both photonic structures cross or intersect in the energy momentum space and produce a cut set of rays of waves on the surfaces of the dispersion functions at a particular energy, wherein a ray of waves contains waves selectively chosen through the filter at an angle, while other waves are reflected by the filter at other angles.