A display device includes: a color filter including a first transmissive filter, a second transmissive filter, and a third transmissive filter, the first, second and third transmissive filters being configured to transmit respective light beams having peak wavelengths different from each other; a first selective-wavelength-reflection layer adjacent to an optical-input surface of the first transmissive filter, the first selective-wavelength-reflection layer being configured to reflect light of a wavelength band that passes through the third transmissive filter; a second selective-wavelength-reflection layer adjacent to an optical-input surface of the second transmissive filter, the second selective-wavelength-reflection layer being configured to reflect light of a wavelength band that passes through the third transmissive filter, the second selective-wavelength-reflection layer being identical in composition to the first selective-wavelength-reflection layer; and a light emitter configured to emit light that travels toward the color filter.

A display panel includes a plurality of sub-pixels. At least one sub-pixel of the plurality of sub-pixels includes a first electrode, a light modulation structure disposed on a side of the first electrode, and a second electrode disposed at a side of the light modulation structure away from the first electrode. The light modulation structure includes a refractive index adjustment layer, and a light modulation layer disposed between the refractive index adjustment layer and the first electrode. A refractive index of the refractive index adjustment layer is changed under action of an electric field between the first electrode and the second electrode. The light modulation layer is in contact with the refractive index adjustment layer, and at least a part of a surface of the light modulation layer that is in contact with the refractive index adjustment layer is a curved face.

Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.

A polarization insensitive optical phase modulator is provided including a glass substrate; a liquid crystal element; a first electrode on a first surface of the liquid crystal element adjacent the glass substrate; a second electrode on a second surface of the liquid crystal element, opposite the first surface, the first and second electrodes supplying an electric potential across the liquid crystal element to drive liquid crystals in a predetermined configuration; and a silicon backplane on the second electrode opposite the liquid crystal element. The first electrode is a transparent electrode to a selected wavelength and is on a surface of the glass substrate. The second electrode includes individually addressable pixels and reflection metal mirrors on pixel surfaces and is on a surface of the silicon backplane. The modulator further includes a polymer quarter-wave plate (QWP) between the second electrode and the liquid crystal element, the polymer QWP having an optical axis at 45 degrees to liquid crystal slow axis.

A light modulation apparatus includes a reflection type spatial light modulator, a polarization separating unit, a first polarization plane rotation unit, a polarization combining unit, and a second polarization plane rotation unit. The polarization separating unit separates input light, and outputs first separated light and second separated light. The first polarization plane rotation unit causes the first separated light to have P-polarization. A first region of a modulation plane of the spatial light modulator modulates the first separated light and outputs first modulated light, and a second region modulates the second separated light and outputs second modulated light. The second polarization plane rotation unit causes the second modulated light to have S-polarization. The polarization combining unit combines the first modulated light and the second modulated light and outputs output light.

An optical device (20) includes an electro-optical layer, including a liquid crystal material (24) with a heliconical structure having a pitch that is less than 250 nm and is modifiable by an electric field. An array of excitation electrodes (28) extends over the electro-optical layer. Control circuitry (23) is coupled to apply control voltage waveforms to the excitation electrodes and is configured to modify the control voltage waveforms so as to locally modify a molecule director angle of the heliconical structure and thus to generate a specified phase modulation profile in the electro-optical layer.

A photonic integrated circuit, an optoelectronic modulator, and a method of modulating light in a photonic integrated circuit are provided. The photonic integrated circuit comprises: an input waveguide which, in use, receives light in a superposition of two polarisation modes of the waveguide; a polarisation splitter, connected to the input waveguide, and configured to provide, at a first output, light in a first polarisation mode of the two polarisation modes of the waveguide and, at a second output, light in a second polarisation mode of the two polarisation modes of the waveguide; a first polarisation rotator, connected to the first output of the polarisation splitter, and configured to rotate light received therefrom from the first polarisation mode to the second polarisation mode; an optoelectronic modulator, having a first modulation waveguide connected to the first polarisation rotator and a second modulation waveguide connected to the second output of the polarisation splitter.

An apparatus includes a dispersive-collimating element, a Faraday material apparatus and a focusing-dispersive element. The dispersive-collimating element assigns each beam wavelength to a particular spatial position. The beams are parallel one to the other. The Faraday material apparatus provides a polarization rotation independently for each wavelength, and the focusing-dispersive element recombines the different wavelengths into one single beam.

A device is provided. The device includes a first lens assembly controllable to switch between a first plurality of optical powers. The first lens assembly includes a plurality of directly optically coupled lenses, and is configured to converge or diverge a light transmitted therethrough. The device also includes a second lens assembly coupled with the first lens assembly, and controllable to switch between a second plurality of optical powers that are opposite to the first plurality of optical powers.

A display device includes: a color filter including a first transmissive filter, a second transmissive filter, and a third transmissive filter, the first, second and third transmissive filters being configured to transmit respective light beams having peak wavelengths different from each other; a first selective-wavelength-reflection layer adjacent to an optical-input surface of the first transmissive filter, the first selective-wavelength-reflection layer being configured to reflect light of a wavelength band that passes through the third transmissive filter; a second selective-wavelength-reflection layer adjacent to an optical-input surface of the second transmissive filter, the second selective-wavelength-reflection layer being configured to reflect light of a wavelength band that passes through the third transmissive filter, the second selective-wavelength-reflection layer being identical in composition to the first selective-wavelength-reflection layer; and a light emitter configured to emit light that travels toward the color filter.