Abstract: 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.

Abstract: An optical device includes: a waveguide array including a plurality of waveguides; and a pulse generator. The waveguides are arranged in a first direction and extend in a second direction intersecting the first direction. The pulse generator inputs, as an input light beam, a light pulse of light to each of the waveguides. The light has a frequency spectrum in air with a maximum peak at a frequency corresponding to a wavelength ?, and the full width at half maximum of the maximum peak is ??. The waveguides propagate the input light beams in the second direction and emit part of the input light beams as emission light. The pulse generator adjusts the difference in phase between input light beams to be inputted to two adjacent waveguides of the plurality of waveguides to thereby change a first direction component of an emission direction of the emission light.

Abstract: An imaging system includes a light-emitting device, an image sensor, and a control circuit. The light-emitting device includes a light source, a first waveguide that propagates light from the light source by means of total reflection, a second waveguide, and a first adjustment element. The control circuit causes the light source to repeatedly emit light pulses. Further, the control circuit causes at least some of the plurality of photo-detection cells to accumulate the signal charge in synchronization with the emission of the light pulses and thereby causes the image sensor to generate every first period of time a frame based on the signal charge thus accumulated. Furthermore, the control circuit causes the first adjustment element to change the direction of the emitted light from the second waveguide every second period of time that is shorter than or equal to half the first period of time.

Abstract: An optical scanning system including an optical scanning device, and a photoreceiver device. The optical scanning device includes: a first waveguide array including a plurality of first waveguides; and a first phase shifter for adjusting phases of light propagating through the plurality of first waveguides to change an emission direction of emission light from the plurality of first waveguides. The photoreceiver device includes: a second waveguide array including a plurality of second waveguides configured to receive reflected light and propagate the received reflected light; and a second phase shifter for adjusting phases of the received reflected light propagating through the plurality of second waveguides to change a reception direction of the reflected light received by the plurality of second waveguides. An array pitch of the plurality of first waveguides in the optical scanning device differs from an array pitch of the plurality of second waveguides in the photoreceiver device.

Abstract: An optical scanning system including an optical scanning device, and a photoreceiver device. The optical scanning device includes: a first waveguide array including a plurality of first waveguides; and a first phase shifter for adjusting phases of light propagating through the plurality of first waveguides to change an emission direction of emission light from the plurality of first waveguides. The photoreceiver device includes: a second waveguide array including a plurality of second waveguides configured to receive reflected light and propagate the received reflected light; and a second phase shifter for adjusting phases of the received reflected light propagating through the plurality of second waveguides to change a reception direction of the reflected light received by the plurality of second waveguides. An array pitch of the plurality of first waveguides in the optical scanning device differs from an array pitch of the plurality of second waveguides in the photoreceiver device.

Abstract: An optical scanning device includes: first and second mirrors; an optical waveguide layer disposed between the first and second mirrors; a pair of electrodes sandwiching the optical waveguide layer; and a driving circuit that applies a voltage to the pair of electrodes. The first mirror has a higher light transmittance than the second mirror and emits part of light propagating through the optical waveguide layer to the outside. The optical waveguide layer contains a liquid crystal material or an electrooptical material. The alignment direction of the liquid crystal material or the direction of a polarization axis of the electrooptical material is parallel or perpendicular to the direction in which the optical waveguide layer extends. The driving circuit applies the voltage to the pair of electrodes to change the refractive index of the liquid crystal material or the electrooptical material to thereby change the light emission direction.

Abstract: An optical scanning system comprises an optical scanning device and a photoreceiver device. The optical scanning device includes a first waveguide array including a plurality of first waveguides through which light beams propagate and from which the light beams are emitted as emission light in an emission direction crossing a propagation direction of the light beams. The photoreceiver device includes a second waveguide array including a plurality of second waveguides disposed in areas on which, when the emission light from the plurality of first waveguides is reflected as reflected light from a target object, the reflected light is incident, the plurality of second waveguides configured to receive the reflected light to propagate the received reflected light as propagating light beams. An array pitch of the plurality of first waveguides in the optical scanning device differs from an array pitch of the plurality of second waveguides in the photoreceiver device.

Abstract: An optical device includes an intermetallic compound of a first metal and a second metal having a lower work function than the first metal, or a solid-solution alloy of the first metal and the second metal and includes an n-type semiconductor in Schottky junction with the intermetallic compound or the solid-solution alloy.

Abstract: An optical device comprises: a light reflection film which includes a metal layer and a dielectric layer on the metal layer; and a phosphor layer which is located on the dielectric layer and which emits light by being excited by light from a light source. The dielectric layer is located between the metal layer and the phosphor layer. A first wavelength, at which a reflectivity of light vertically incident on the light reflection film from the phosphor layer is highest, is longer than a centroid wavelength of an emission spectrum of the phosphor layer. The dielectric layer has a layered structure comprising a plurality of layers composed of at least two but no more than six layers. Refractive indexes of any two adjacent layers of the plurality of layers are different from each other.

Abstract: An optical scanning device including: a first mirror having a first reflecting surface; a second mirror having a second reflecting surface; two non-waveguide regions disposed between the first and second mirrors and that are spaced apart from each other in a first direction parallel to at least either the first reflecting surface or the second reflecting surface; and an optical waveguide region disposed between the first and second mirrors and that is sandwiched between the two non-waveguide regions. The optical waveguide region propagates light in a second direction that crosses the first direction. The optical waveguide region and the two non-waveguide regions include respective first regions in which a common material exists. The optical waveguide region or each of the two non-waveguide regions further includes a second region in which a first material having a refractive index different from the refractive index of the common material exists.

Abstract: A light-emitting apparatus includes an excitation light source that emits first light; a light-emitting device on an optical path of the first light, the light-emitting device emitting second light having a wavelength in air; and a first converging lens on an optical path of the second light. The light-emitting device comprises: a photoluminescent layer that emits the second light by being excited by the first light; and a light-transmissive layer on the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a surface structure comprising projections or recesses arranged perpendicular to a thickness direction of the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction, the second light emitted from the light emitting surface. The surface structure limits the directional angle of the second light emittied from the light emitting surface.

Abstract: An optical scanning device including: a first mirror having a first reflecting surface; a second mirror having a second reflecting surface; two non-waveguide regions disposed between the first and second mirrors and that are spaced apart from each other in a first direction parallel to at least either the first reflecting surface or the second reflecting surface; and an optical waveguide region disposed between the first and second mirrors and that is sandwiched between the two non-waveguide regions. The optical waveguide region propagates light in a second direction that crosses the first direction. The optical waveguide region and the two non-waveguide regions include respective first regions in which a common material exists. The optical waveguide region or each of the two non-waveguide regions further includes a second region in which a first material having a refractive index different from the refractive index of the common material exists.

Abstract: An optical scanning device includes: a first mirror; a second mirror; two non-waveguide regions; an optical waveguide region; and a first adjusting element. The optical waveguide region propagates light. The optical waveguide region and the two non-waveguide regions include respective first regions in which a common material exists. The optical waveguide region or each of the two non-waveguide regions further includes a second region in which a first material having a refractive index different from a refractive index of the common material exists. The first mirror allows part of the light propagating through the optical waveguide region to be emitted through the first mirror. The first adjusting element changes at least either the average refractive index of the optical waveguide region or a thickness of the optical waveguide region to change a direction of the light emitted through the first mirror.

Abstract: An optical scanning device comprises: a first mirror that has a first reflecting surface; a second mirror that has a second reflecting surface, and that faces the first mirror; an optical waveguide region that is disposed between the first mirror and the second mirror and that propagates light in a direction parallel to at least either the first reflecting surface or the second reflecting surface; and a first adjusting element that changes at least either an average refractive index of the optical waveguide region or a thickness of the optical waveguide region. The optical waveguide region contains a liquid. Each of the first and second mirrors includes a portion in contact with the optical waveguide region.

Abstract: An optical scanning device includes: a first mirror; a second mirror; two non-waveguide regions; an optical waveguide region; and a first adjusting element. The optical waveguide region propagates light. The optical waveguide region and the two non-waveguide regions include respective first regions in which a common material exists. The optical waveguide region or each of the two non-waveguide regions further includes a second region in which a first material having a refractive index different from a refractive index of the common material exists. The first mirror allows part of the light propagating through the optical waveguide region to be emitted through the first mirror. The first adjusting element changes at least either the average refractive index of the optical waveguide region or a thickness of the optical waveguide region to change a direction of the light emitted through the first mirror.

Abstract: A light-emitting apparatus includes; a light-emitting device including a photoluminescent layer that receives excitation light and emits light including first light having a wavelength ?a in air, and a light-transmissive layer located on or near the photoluminescent layer; and an optical fiber that receives the light from the photoluminescent layer at one end of the optical fiber and emits the received light from the other end thereof. A surface structure is defined on at least one of the photoluminescent layer and the light-transmissive layer, and the surface structure has projections or recesses or both and limits a directional angle of the first light having the wavelength ?a in air.

Abstract: An optical scanning device includes: a first waveguide that propagates light by total reflection; and a second waveguide. The second waveguide includes: a first multilayer reflective film; a second multilayer reflective film that faces the first multilayer reflective film; and a first optical waveguide layer directly connected to the first waveguide and located between the first and second multilayer reflective films. The first optical waveguide layer has a variable thickness and/or a variable refractive index and propagates the light transmitted through the first waveguide. The first multilayer reflective film has a higher light transmittance than the second multilayer reflective film and allows part of the light propagating through the first optical waveguide layer to be emitted to the outside. By changing the thickness of the first optical waveguide layer and/or its refractive index, the direction of the part of the light emitted from the second waveguide is changed.

Abstract: An optical scanning device includes a waveguide array including a plurality of waveguides arranged in a first direction. Each waveguide includes: an optical waveguide layer that propagates light supplied to the waveguide in a second direction intersecting the first direction; a first mirror having a first reflecting surface intersecting a third direction; and a second mirror having a second reflecting surface that faces the first reflecting surface. The optical waveguide layer is located between the first and second mirrors and has a variable thickness and/or a variable refractive index for the light. The width of the first mirror and the width of the second mirror are each larger than the width of the optical waveguide layer. The first mirror has a higher light transmittance than the second mirror and allows part of the light propagating through the optical waveguide layer to be emitted in the third direction.

Abstract: An optical scanning device comprises a waveguide array, a first adjusting element, a plurality of phase shifters, a second adjusting element, and a control circuit. When light emitted from the waveguide array forms a light spot on a virtual plane that is spaced apart from the waveguide array, the control circuit causes the light spot to move in first and second directions such that the distance of movement of the light spot from start to finish of scanning of a target region is greater in first one of the first and second directions than in second one of the first and second directions.

Abstract: A light-emitting device comprises a photoluminescent layer that emits light including first light in an infrared region; and a light-transmissive layer located on the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a periodic structure having projections or recesses or both arranged perpendicular to the thickness direction of the photoluminescent layer. At least one of the photoluminescent layer and the light-transmissive layer has a light emitting surface perpendicular to the thickness direction of the photoluminescent layer, the first light being emitted from the light emitting surface. A refractive index nwav-a of the photoluminescent layer for the first light and a period pa of the periodic structure satisfy ?a/nwav-a<pa<?a. A thickness of the photoluminescent layer, the refractive index nwav-a and the period pa are set to limit a directional angle of the first light emitted from the light emitting surface.