Abstract: A waveguide device includes: a photonic crystal layer having holes periodically formed in an electro-optical crystal substrate; a line-defect optical waveguide formed in the photonic crystal layer; a first electrode arranged above the electro-optical crystal substrate, the first electrode being transparent to light; and a second electrode arranged below the electro-optical crystal substrate. Each of an optical scanning device and an optical modulation device includes the above-mentioned waveguide device.

Abstract: The waveguide element includes: a dielectric portion having holes periodically formed in a substrate made of a ceramics material; a low-dielectric constant portion having a dielectric constant smaller than a dielectric constant of the dielectric portion; and a support substrate arranged below the dielectric portion, the support substrate being configured to support the dielectric portion. The waveguide element is configured to guide an electromagnetic wave having a frequency of 30 GHz or more and 20 THz or less, and a frequency range of the electromagnetic wave in which an absolute value of a propagation loss becomes 1 dB/cm or less is 50 GHz or more.

Abstract: A composite substrate includes: a piezoelectric layer; and a reflective layer arranged on a back surface side of the piezoelectric layer, the reflective layer including a low-impedance layer containing silicon oxide and a high-impedance layer, wherein the piezoelectric layer has a modified layer formed in an end portion on the back surface side thereof, and wherein the low-impedance layer has a density of 2.15 g/cm3 or more.

Abstract: A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

Abstract: An acoustic wave device includes a piezoelectric material substrate, an intermediate layer on the piezoelectric material substrate and composed of one or more materials selected from the group consisting of silicon oxide, aluminum nitride and sialon. A bonding layer is on the intermediate layer and is composed of one or more materials selected from the group consisting of tantalum pentoxide, niobium pentoxide, titanium oxide, mullite, alumina, and a high resistance silicon and hafnium oxide. A supporting body is composed of a polycrystalline ceramic and is bonded to the bonding layer by direct bonding, and an electrode is on the piezoelectric material substrate.

Abstract: Provided is a photonic crystal element, which shows small delay of an electric signal, shows a small propagation loss, and has uniform characteristics over its entirety. The photonic crystal element includes a two-dimensional photonic crystal slab having holes periodically formed in a substrate made of a ceramics material, the photonic crystal element being configured to guide an electromagnetic wave having a frequency of 30 GHz or more and 20 THz or less.

Abstract: Provided is an optical scanning element, which has a large scan angle, is quickly responsive, and can be downsized. The optical scanning element includes: a photonic crystal layer having holes periodically formed in an electro-optical crystal substrate; a line-defect optical waveguide formed in the photonic crystal layer; a diffraction grating arranged in at least one portion selected from an upper portion, a left side surface portion, and a right side surface portion of the optical waveguide; and electrodes arranged on a left side and a right side of the optical waveguide. The optical scanning element is configured so that an emission angle of light emitted from an upper surface of the optical waveguide is changed.

Abstract: A composite substrate (100) for a photonic crystal element includes: an electro-optical crystal substrate (10) having an electro-optical effect; an optical loss-suppressing and cavity-processing layer (20) arranged on one surface of the electro-optical crystal substrate (10); and a support substrate (30) integrated with the electro-optical crystal substrate (10) through the optical loss-suppressing and cavity-processing layer (20).

Abstract: A vibrating plate-bonded body includes a supporting substrate composed of silicon, a vibrating plate composed of a highly rigid ceramics and having a thickness of 100 ?m or smaller, and a bonding layer between the supporting substrate and vibrating plate, contacting a bonding surface of the vibrating plate and composed of ?-Si. The arithmetic average roughness Ra of the bonding surface of the vibrating plate is 0.01 nm or more and 10.0 nm or less, and the pit density of the bonding surface of the vibrating plate is 10 counts or more per 100 ?m2.

Abstract: A composite substrate includes: a piezoelectric layer; and a reflective layer arranged on a rear surface side of the piezoelectric layer, wherein the reflective layer includes a high-impedance layer and a low-impedance layer containing silicon oxide, and wherein a ratio of a region of first structures in the high-impedance layer is more than 70%.

Abstract: A vibrating plate-bonded body includes a supporting substrate composed of silicon, a vibrating plate composed of a highly rigid ceramics and having a thickness of 100 ?m or smaller, and a bonding layer between the supporting substrate and vibrating plate, contacting a bonding surface of the vibrating plate and composed of ?-Si. The arithmetic average roughness Ra of the bonding surface of the vibrating plate is 0.01 nm or more and 10.0 nm or less, and the pit density of the bonding surface of the vibrating plate is 10 counts or more per 100 ?m2.

Abstract: A piezoelectric vibrating device includes a piezoelectric layer composed of a bulk piezoelectric material, a lower electrode on a first surface of the piezoelectric layer and a supporting substrate bonded with the lower electrode.

Abstract: A piezoelectric monocrystalline substrate is composed of a material represented by LiAO3 (A represents at least one element selected from the group consisting of niobium and tantalum), a bonding layer is compose of a material of an oxide of at least one element selected from the group consisting of niobium and tantalum, and an interface layer is provided along an interface between the piezoelectric monocrystalline substrate 6 and bonding layer, and the interface layer has a composition of ExO(1-x) (E represents at least one element selected from the group consisting of niobium and tantalum and 0.29?x?0.89).

Abstract: 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.

Abstract: A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

Abstract: There is provided a composite substrate in which peeling is significantly suppressed, light propagation loss is small when used as an electro-optical element, and high-speed and low-voltage drive is possible, and which can achieve an extremely thin electro-optical element capable of maintaining excellent reliability even under a severe high-temperature environment. A composite substrate for an electro-optical element according to an embodiment of the present invention includes: an electro-optical crystal substrate having an electro-optical effect; a first high dielectric layer; a second high dielectric layer; and a support substrate in the stated order. The first high dielectric layer and the second high dielectric layer are directly joined to each other, and an amorphous layer is formed at a joining interface between the first high dielectric layer and the second high dielectric layer.

Abstract: A bonded body includes a supporting substrate, piezoelectric material substrate and a multilayer film, between the supporting substrate and piezoelectric material substrate. The multilayer film includes a lamination structure having a first layer, second layer, third layer and fourth layer in the order. The first layer and third layer are composed of silicon oxides, and the second layer and fourth layer are composed of metal oxides. The refractive index of the second layer is higher than the refractive index of the first layer and refractive index of the third layer. The refractive index of the second layer is different from the refractive index of the fourth layer.

Abstract: A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

Abstract: A vibrating plate-bonded body includes a supporting substrate composed of silicon, a vibrating plate composed of a highly rigid ceramics and having a thickness of 100 ?m or smaller, and a bonding layer between the supporting substrate and vibrating plate, contacting a bonding surface of the vibrating plate and composed of ?-Si. The arithmetic average roughness Ra of the bonding surface of the vibrating plate is 0.01 nm or more and 10.0 nm or less, and the pit density of the bonding surface of the vibrating plate is 10 counts or more per 100 ?m2.

Abstract: A phosphor device includes a phosphor layer composed of a phosphor glass or phosphor single crystal, a reflective film provided on the phosphor layer, a warping suppression layer provided on the reflective film, and a supporting body bonded to the warping suppression layer by direct bonding. An excitation light incident into the phosphor layer is converted to fluorescence, and the fluorescence and excitation light are reflected by the reflective film and emitted from the phosphor layer.