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: A member for terahertz equipment includes: a substrate main body having a first principal surface and a second principal surface; and a reflection suppressing portion provided on at least one of the first principal surface or the second principal surface of the substrate main body. The reflection suppressing portion includes a plurality of protrusions which are arranged in a grating shape, and each have a tapered portion in a vertical cross section.

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 for an electro-optic element includes: an electro-optic crystal substrate having an electro-optic effect; a support substrate bonded to the electro-optic crystal substrate at least via an amorphous layer; and a low-refractive-index layer located between the electro-optic crystal substrate and the amorphous layer and having a lower refractive index than the electro-optical crystal substrate. The amorphous layer is constituted of one or more elements that constitute a layer or a substrate contacting the amorphous layer from one side and one or more elements that constitute a layer or a substrate contacting the amorphous layer from another side.

Abstract: There is provided an optical scanning element, which has a large scan angle, is quickly responsive, and can be downsized. An optical scanning element according to an embodiment of the present invention includes: a first light-deflecting unit for emitting light to a first area; and a second light-deflecting unit for emitting the light that has been emitted to the first area to a second area wider than the first area. The first light-deflecting unit is configured to be changed in refractive index by a change in applied voltage, and to adjust the first area through the change in refractive index, and the second light-deflecting unit is configured to adjust the second area through diffraction.

Abstract: A phosphor element includes an incident face for an excitation light, a reflecting face opposing the incident face and a side face, and the phosphor element converts at least a part of the excitation light incident onto the incident face into a fluorescence and emits the fluorescence from the incident face. The incident face has an area greater that an area of the reflecting face. The phosphor element includes an inclination region in which an inclination angle of the side face with respect to a vertical axis perpendicular to the incident face is monotonously increased from the reflecting face toward the incident face, viewed in a cross-section perpendicular to the incident face and along the longest dividing line halving the incident face.

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 composite substrate for an electro-optic element includes: an electro-optic crystal substrate having an electro-optic effect; a support substrate bonded to the electro-optic crystal substrate at least via an amorphous layer; and a low-refractive-index layer located between the electro-optic crystal substrate and the amorphous layer and having a lower refractive index than the electro-optical crystal substrate. The amorphous layer is constituted of one or more elements that constitute a layer or a substrate contacting the amorphous layer from one side and one or more elements that constitute a layer or a substrate contacting the amorphous layer from another side.

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 composite substrate for an electro-optic element includes: an electro-optic crystal substrate having an electro-optic effect; a support substrate bonded to the electro-optic crystal substrate at least via an amorphous layer; and a low-refractive-index layer located between the electro-optic crystal substrate and the amorphous layer and having a lower refractive index than the electro-optical crystal substrate. The amorphous layer is constituted of one or more elements that constitute a layer or a substrate contacting the amorphous layer from one side and one or more elements that constitute a layer or a substrate contacting the amorphous layer from another side.

Abstract: A white light generating device, for generating white light from an excitation light of a laser light having a wavelength of from 280 nm-495 nm, includes a fluorescent body generating a fluorescence having a wavelength longer than a wavelength of the excitation light. The fluorescent body includes an emission-side end surface emitting excitation light and fluorescence, an opposing end surface on an opposite side of the emission-side end surface, and an outer peripheral surface. The emission-side end surface has an area larger than an area of the opposing end surface, and the outer peripheral surface of the fluorescent body includes a part inclined with respect to a central axis of the fluorescent body by from 3.4°-23° over an entire periphery of the fluorescent body. The emission-side end surface has an area of from 0.3 mm2-1.52 mm2.

Abstract: A white light generating device, for generating white light from an excitation light of a laser light having a wavelength of from 280 nm-495 nm, includes a fluorescent body generating a fluorescence having a wavelength longer than a wavelength of the excitation light. The fluorescent body includes an emission-side end surface emitting excitation light and fluorescence, an opposing end surface on an opposite side of the emission-side end surface, and an outer peripheral surface. The emission-side end surface has an area larger than an area of the opposing end surface, and the outer peripheral surface of the fluorescent body includes a part inclined with respect to a central axis of the fluorescent body by from 3.4°-23° over an entire periphery of the fluorescent body. The emission-side end surface has an area of from 0.3 mm2-1.52 mm2.

Abstract: A bonded body for an optical modulator includes a supporting substrate, an optical waveguide material provided on the supporting substrate and composed of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate, and an optical waveguide in the optical waveguide material. The supporting substrate is composed of a material selected from the group consisting of magnesium oxide and a magnesium-silicon composite oxide.

Abstract: A phosphor element includes an incident face for an excitation light, an emitting face opposing the incident face and a side face, and the element converts at least a part of the incident excitation light incident onto the incident face to fluorescence and emits the fluorescence from the emitting face. The emitting face has an area larger than an area of the incident face. The phosphor element comprises an inclination region in which an inclination angle of the side face with respect to a vertical axis perpendicular to the emitting face is monotonously increased from the incident face toward the emitting face, viewed in a cross-section perpendicular to the emitting face and along the longest dividing line halving the emitting face.

Abstract: A phosphor element includes an incident face for an excitation light, a reflecting face opposing the incident face and a side face, and the phosphor element converts at least a part of the excitation light incident onto the incident face into a fluorescence and emits the fluorescence from the incident face. The incident face has an area greater that an area of the reflecting face. The phosphor element includes an inclination region in which an inclination angle of the side face with respect to a vertical axis perpendicular to the incident face is monotonously increased from the reflecting face toward the incident face, viewed in a cross-section perpendicular to the incident face and along the longest dividing line halving the incident face.

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.