Examples are disclosed relating to reducing orders of diffraction patterns in phase modulating devices. An example phase modulating device includes a phase modulating layer having first and second opposing sides, a common electrode adjacent the first side of the phase modulating layer, a plurality of pixel electrodes adjacent the second side of the phase modulating layer, and blurring material disposed between the phase modulating layer and the pixel electrodes. In the example phase modulating device, the blurring material is configured to smooth phase transitions in the phase modulating layer between localized areas associated with the pixel electrodes, the pixel electrodes have a pixel pitch by which the pixel electrodes are distributed along the phase modulating layer, and the pixel electrodes are separated from one another by an inter-pixel gap, where the ratio of the inter-pixel gap to the pixel pitch is between 0.50 and 1.0.

A system for uniform optical illumination of an image light provider in a smaller (compact) configuration than conventional implementations includes a lightguide having: a first external surface and a second external surface mutually parallel, and a first sequence of facets, at least a portion of which are: a plurality of parallel, partially reflecting, and polarization selective surfaces, at an oblique angle relative to the first and second external surfaces, and between the first and second external surfaces, and a front-lit reflective polarization rotating image modulator: deployed to spatially modulate light coupled-out from the first external surface, outputting reflected light corresponding to an image, and deployed such that the reflected light traverses the lightguide from the first external surface via the first sequence of facets to the second external surface.

Method for determining the characteristics of a system for generating at least one pattern of light, the method comprising: a) providing a desired pattern of light, b) expressing the amplitude and the phase of the output pulse of the system as a function of the input laser pulse and in function of the characteristics of the system to obtain a calculated output pulse, the input laser pulse having a duration below or equal to 1 nanosecond, c) determining at least one characteristic of the system by minimizing a distance between the calculated output pulse and the desired output laser pulse.

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.

A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. A birefringent surface relief diffuser structure is arranged to transmit light from the display with high transparency and provide diffuse reflection of ambient light to head-on display users. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss and with low diffusion, whereas off-axis light has reduced luminance and increased diffusion. Further, overall display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction, increased frontal reflectivity and diffusion of ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

A light irradiation device is an apparatus for irradiating an irradiation object, and includes a light source outputting readout light L1, a spatial light modulator modulating the readout light L1 in phase to output modulated light L2, and a both-sided telecentric optical system including a first lens optically coupled to a phase modulation plane of the spatial light modulator and a second lens optically coupled between the first lens and the irradiation object, and optically coupling the phase modulation plane and the irradiation object. An optical distance between the phase modulation plane and the first lens is substantially equal to a focal length of the first lens. The spatial light modulator displays a Fresnel type kinoform on the phase modulation plane.

An apparatus for improving contrast in an image captured by an imaging sensor. The apparatus including: an objective optical system positioned in an optical path of illumination light on an object; an image sensor positioned in the optical path such that light from the objective optical system is incident on the image sensor; a device having a variable transparency positioned at a focal plane of the objective optical system; and a processor configured to: detect a bright spot on the image sensor; and control the device to change a transparency of a portion of the device corresponding to the detected bright spot.

An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. The directional backlight may be arranged to switch between at least a first wide angular luminance profile mode and a second narrow angular luminance profile mode. The directional backlight is arranged to illuminate an LCD with a bias electrode arranged to switch liquid crystal directors in black state pixels between a first wide angular contrast profile mode and a second narrow angular contrast profile mode. Performance of privacy operation for off-axis snoopers is enhanced in comparison to displays with only directional backlights or switchable contrast properties.

A coherent frequency modulated receiver for receiving and detecting arriving optical signals which comprises an electrically controllable optical beam scanner receiving optical input beams arriving at different angles in a field of view of the electrically controllable optical beam scanner, the electrically controllable optical beam scanner conveying a scanned optical input beam as its output optical beam; a grating coupler responsive to the output or reflected optical beam of the electrically controllable optical beams scanner, the grating coupler having a waveguided output; an optical local oscillator laser having a waveguided output; an FMCW signal generator; an optical modulator responsive to the optical waveguided outputs of the optical local oscillator laser and also to an electrical FMCW signal from the FMCW signal generator; a pair of second order non-linear optical elements for frequency upconverting respective outputs of the optical modulator and the grating coupler; and at least one photodiode optically coupled to an outputs of the pair of second order non-linear optical elements.

A sub-pixel unit for a reflective display includes a color filter including a tunable high contrast grating. The tunable high contrast grating reflects light within a first range of wavelengths, and the sub-pixel unit can exist in a first state and a second state, the first state reflecting at least one of (i) light within a different range of wavelengths, and (ii) light of a different intensity level, than the second state.