Methods and apparatus for a photonic acoustic-optic frequency shifter having an integrated layer of lithium niobate. An input port receives input light and an acoustic wave generator generates an acoustic wave into a deflection area comprising a layer of lithium niobate. A first output port exits undeflected light from the deflection area as transmitted light and a second output port exits light deflected in frequency by the acoustic wave in the deflection area.

Methods and apparatus for a photonic acoustic-optic frequency shifter having an integrated layer of lithium niobate. An input port receives input light and an acoustic wave generator generates an acoustic wave into a deflection area comprising a layer of lithium niobate. A first output port exits undeflected light from the deflection area as transmitted light and a second output port exits light deflected in frequency by the acoustic wave in the deflection area.

A sensing system adapted to receive backscattered signal from a sensing fiber includes a first Faraday rotator mirror; a second Faraday rotator mirror; an optical hybrid coupled to the Faraday rotator mirrors, wherein one of the mirrors is coupled with an optical path difference; a 3-port optical circulator coupled to the sensing fiber and the optical hybrid; a first photodetector coupled to the circulator; and three photodetectors coupled to the optical hybrid.

A sensing system adapted to receive backscattered signal from a sensing fiber includes a first Faraday rotator mirror; a second Faraday rotator mirror; an optical hybrid coupled to the Faraday rotator mirrors, wherein one of the mirrors is coupled with an optical path difference; a 3-port optical circulator coupled to the sensing fiber and the optical hybrid; a first photodetector coupled to the circulator; and three photodetectors coupled to the optical hybrid.

Provided is a display device comprising a liquid-crystal panel and an optical sheet member including multiple stacked optical sheets emitting light from a light source toward the liquid-crystal panel, which can alleviate unevenness in light even in the case where, for example, light with such unevenness is emitted from the optical sheet member due to warps or wrinkles generated in the optical sheet member caused by heat generated by the light source. A diffusion sheet is provided between a liquid-crystal panel and an optical sheet member with a gap from the optical sheet member. The light emitted through the optical sheet member is diffused by the diffusion sheet and gap, and then enters the liquid-crystal panel.

A switchable grating may be used to redirect illuminating light for illuminating a user’s eye in an eye tracking system, to facilitate the determination of eye position and/or orientation. The eye tracking system may be used in a near-eye display. An eye tracking camera obtains an eye image, and a controller performs an initial determination of the eye position. The controller may switch the switchable grating to direct the illuminating light beam onto the eye, for a better position and/or eye orientation determination.

A switchable grating may be used to redirect illuminating light for illuminating a user’s eye in an eye tracking system, to facilitate the determination of eye position and/or orientation. The eye tracking system may be used in a near-eye display. An eye tracking camera obtains an eye image, and a controller performs an initial determination of the eye position. The controller may switch the switchable grating to direct the illuminating light beam onto the eye, for a better position and/or eye orientation determination.

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.

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 light field generator system including a leaky-mode SAW modulator is disclosed. The modulator incorporates at least one optical power component, such as a concave mirror or volume grating having a non-zero diopter rating. In some embodiments, the system incorporates the at least one optical power component by embedding the optical power component within a substrate of the SAW modulator and/or by placing the optical power component upon a surface of the SAW modulator.