A waveguide grating antenna apparatus includes a substrate layer, a lower waveguide array layer upon the substrate, and an upper waveguide array layer positioned above the lower waveguide array layer. The lower waveguide array layer is composed of a plurality of first waveguides extending axially and a plurality of second waveguides extending axially and arranged in parallel and alternating in position with the plurality of first waveguides across the lower waveguide array layer. Each first waveguide is of a first maximum width. Each second waveguide is of a second maximum width narrower than the first maximum width and is spaced apart from each adjacent first waveguide. The upper waveguide array layer is composed of adjacent, separated elements extending axially along each first waveguide and each second waveguide.

An optical beam scanning semiconductor device includes 1×N electrically controlled, integrated optical switch matrix and specifically designed integrated optical grating output couplers at each of N output waveguides of 1×N switch. By selecting one of the N outputs of the 1×N switch as the output of the input optical signal, an optical output beam scans in free space. Variation in the grating output coupler design enables a smart scanning device with multiple controllable beam characteristics.

A method for implementing folding M×N wavelength selective switch is provided. A one-dimensional single-mode fiber optic collimator array, a short-focus cylindrical mirror, a first long-focus cylindrical mirror, a retroreflector, a transmission phase diffraction grating, a second long-focus cylindrical mirror, a liquid crystal spatial light modulator, and a liquid crystal graphic loading control system are provided along beam transmission direction. The same set of optical elements is used for incident light and outgoing light by ingenious folding structure. The input port and output port of optical signal are consistent in spatial arrangement, thereby reducing space and improving port utilization. Based on composite liquid crystal chips, a working area of the liquid crystal spatial light modulator is doubled, and a quantity of accommodating ports is greatly increased. A quantity of M×N ports of the WSS can be increased greatly by the above structure and design.

A lightguide for conveying image light to an eyebox of a display device includes a tunable grating, e.g. an out-coupling grating for out-coupling the image light from the lightguide. The tunable grating may be tuned or switched to effectively diffract light of a color channel of a color-sequential display. In augmented reality display systems, a lightguide combiner element may include a switchable grating to out-couple the image light only during short time intervals and to not out-couple the image light in between these time intervals. Effectively, the out-coupling grating is present only a portion of overall operation time of the display, which improves the transparency of the combiner element to the outside light and reduces rainbow effects.

A lightguide for conveying image light to an eyebox of a display device includes a tunable grating, e.g. an out-coupling grating for out-coupling the image light from the lightguide. The tunable grating may be tuned or switched to effectively diffract light of a color channel of a color-sequential display. In augmented reality display systems, a lightguide combiner element may include a switchable grating to out-couple the image light only during short time intervals and to not out-couple the image light in between these time intervals. Effectively, the out-coupling grating is present only a portion of overall operation time of the display, which improves the transparency of the combiner element to the outside light and reduces rainbow effects.

A display apparatus includes a lightguide for conveying images to a user in a target field-of-view (FOV). The lightguide includes a tunable output diffraction grating for displaying different portions of the target field-of-view at different time instances. The tunable output diffraction grating may include grating segments that are selectively switchable between a diffracting state and a non-diffracting state in dependence on a content of an image being displayed, providing content-dependent FOV switching.

In a light deflection device and a lidar device, a parallel operation can be realized with a simple constitution, so as to avoid enlargement or complication of a system. The reflection angle of the light deflection device depends on a wavelength and a refractive index, so that light beams with respective wavelengths different from each other are simultaneously and parallelly deflected in directions of deflection angles each defined by the wavelength and the refractive index. The light beams with the plural wavelengths different from each other are deflected at the different deflection angles each defined by each wavelength and the refractive index, so that they can be deflected simultaneously and parallelly. The plural deflected light beams can be distinguished from each other based on the difference in the wavelength and the deflection angle of the light, even in the simultaneous and parallel operation.

An optical scanning device includes: a first mirror; a second mirror opposed to the first mirror; two non-waveguide regions sandwiched between the first mirror and the second mirror; an optical waveguide region disposed between the two non-waveguide regions; and two intermediate regions. The average refractive index of the optical waveguide region is higher than the average refractive index of each intermediate region. The average refractive index of each intermediate region is higher than the average refractive index of each non-waveguide region. The first mirror allows part of light propagating through the optical waveguide region to be emitted as emission light in a third direction. By changing the refractive index and/or thickness of the optical waveguide region, the third direction, which is the emission direction of the emission light, is changed.

A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.

An optical scanning device includes a supporting body 2; an optical waveguide composed of a single crystal having electro-optic effect and integrated with the supporting body directly or through a clad layer; a plurality of periodic domain inversion parts formed in the optical waveguide, the periodic domain inversion parts having periods different from each other; and a plurality of electrodes capable of applying voltages on the periodic domain inversion parts, respectively, to generate diffraction gratings in the periodic domain inversion parts, respectively. The clad layer is composed of a material having a refractive index lower than a refractive index of the single crystal forming the optical waveguide. Each of the periodic domain inversion parts on which the voltage is applied is selected to generate the diffraction grating in the selected periodic domain inversion part so that a propagation light propagated in the optical waveguide is emitted to the outside of the optical scanning device as a diffracted light.