An Electrically Switchable Bragg Grating (ESBG) despeckler device comprising at least one ESBG element recorded in a hPDLC sandwiched between transparent substrates to which transparent conductive coatings have been applied. At least one of said coatings is patterned to provide a two-dimensional array of independently switchable ESBG pixels. Each ESBG pixel has a first unique speckle state under said first applied voltage and a second unique speckle state under said second applied voltage.

An optical waveguide comprises at least two TIR surface and contains a grating. Input TIR light with a first angular range along a first propagation direction undergoes at least two diffractions at the grating. Each diffraction directs light into a unique TIR angular range along a second propagation direction.

Holographic volume gratings in waveguide cells can be recorded using many different methods and systems in accordance with various embodiments of the invention. One embodiment includes a holographic recording system including at least one laser source configured to emit recording beams and a movable platform configured to move between a first position and a second position, wherein when the movable platform is in the first position, the at least one laser source is configured to emit a first set of one or more recording beams toward a first set of one or more stations and when the movable platform is in the second position, the at least one laser source is configured to emit a second set of one or more recording beams toward a second set of one or more stations.

An optical apparatus includes an image source, a relay optical system, and an optical processing system. The image source is configured to display an image. The relay optical system is configured to project the image displayed by the image source to the optical processing system, and to image at infinity. The optical processing system is configured to project incident light from the relay optical system in a same direction to at least two preset directions sequentially.

Examples are disclosed relating to tunable attenuation of incident light using a switchable grating. One example provides an optical attenuator comprising a switchable grating configured to diffract light within a wavelength band at a diffraction angle. The optical attenuator further comprises an electrode pair configured to apply a voltage across the switchable grating to tune a proportion of incident light diffracted at the diffraction angle, and an optical dump to receive the proportion of incident light diffracted.

A device for reducing laser speckle using a micro scanner and a holographic diffuser. The micro scanner includes a first transparent optical substrate with an input surface and an output surface and a second transparent optical substrate with an input surface and an output surface and a variable refractive index medium sandwiched between the output surface of the first substrate and the input surface of the second substrate. Transparent electrodes are applied to the output surface of the first substrate and the input surface of the second substrate. The electrodes are coupled to a voltage generator. The input surface of the first substrate is optically coupled to a laser source. The input surface of the second substrate is configured as an array of prismatic elements. At least one of the input surface of the first substrate or the output surfaces of the second substrate is planar.

A panel for fingerprint identification and a control method thereof, and an apparatus for fingerprint identification. The panel for fingerprint identification includes: a display unit, a control unit, a unit for adjusting light transmittance and a unit for fingerprint identification which are disposed on a backlight side of the display unit, wherein an operating state of the panel for fingerprint identification includes: a display stage and a fingerprint identification stage. At the display stage, the display unit is configured to emit first light to display an image to be displayed, the unit for adjusting light transmittance is configured to transmit light transmitted through the display unit, and the control unit is connected with the unit for adjusting light transmittance and is configured to control the light transmittance of the unit for adjusting light transmittance.

A device includes a first substrate and a second substrate. The device also includes a birefringent medium layer disposed between the first substrate and the second substrate. Orientations of directors of optically anisotropic molecules included in the birefringent medium layer varying periodically with an in-plane pitch tunable by an external field to adjust a diffraction angle of a light beam diffracted by the birefringent medium layer.

Various embodiments of this disclosure relate to a piecewise varying rolled K-vector grating structure including: a first grating section containing a grating with a first K-vector, a second grating section containing a grating with a second K-vector; and a first boundary region positioned between the first grating section and the second grating section. The first boundary region is a multiplexed grating region including both the first K-vector and the second K-vector. Further disclosed is a method for recording such a grating structure utilizing a holographic recording process. Providing a multiplexed grating in the first boundary region may largely remove line exposure artifacts between adjacent sections of the P-RKV grating.

A device is provided. The device includes a polarization hologram polymer layer having a wavy surface, an optic axis of the polarization hologram polymer layer being configured with a spatially varying orientation in a first predetermined in-plane direction. The device also includes a compensation layer disposed at the wavy surface of the polarization hologram polymer layer and configured to compensate for the wavy surface in shape.