Abstract: A composite substrate 10 includes a semiconductor substrate 12 and an insulating support substrate 14 that are laminated together. The support substrate 14 includes first and second substrates 14a and 14b made of the same material and bonded together with a strength that allows the first and second substrates 14a and 14b to be separated from each other with a blade. The semiconductor substrate 12 is laminated on a surface of the first substrate 14a opposite a surface thereof bonded to the second substrate 14b.

Abstract: A handle substrate of a composite substrate for a semiconductor is provided. The handle substrate is composed of polycrystalline alumina. The handle substrate includes an outer peripheral edge part with an average grain size of 20 to 55 ?m and a central part with an average grain size of 10 to 50 ?m. The average grain size of the outer peripheral edge part is 1.1 times or more and 3.0 times or less of that of the central part of the handle substrate.

Abstract: In a handle substrate for a composite wafer for a semiconductor, particles from the wafer with a notch formed therein are reduced. The handle substrate 1A or 1B for the composite wafer for the semiconductor is formed of a polycrystalline ceramic sintered body, and includes a notch 2A or 2B in its outer peripheral portion. The notch is formed with an as-sintered surface.

Abstract: It is provided an insulating substrate including through holes 2 for conductors arranged in the insulating substrate. A thickness of the insulating substrate is 25 to 300 ?m , and a diameter of the through hole is 20 to 100 ?m . The insulating substrate is composed of an alumina sintered body. A relative density and an average grain size of the alumina sintered body is 99.5 percent or higher and 2 to 50 ?m , respectively.

Abstract: A handle substrate 1 is made of a translucent ceramics. An average density of pores having a size of 0.6 to 3.0 ?m included in a surface region 2A on the side of a bonding face 1a of the handle substrate 1 is 50 counts/mm2 or smaller. It is formed a region 3, whose average density of pores having a size of 0.5 to 3.0 ?m is 100 counts/mm2 or larger, in the handle substrate 1. The translucent ceramics has an average grain size of 5 to 60 ?m.

Abstract: A handle substrate 11 or 11A is formed of an insulating polycrystalline material, the handle substrate has a surface 15 having a microscopic central line average surface roughness Ra of 5 nm or smaller, and height differences 3 are provided between exposed faces 2a of crystal grains 2 exposing to said surface 15.

Abstract: A composite substrate for a semiconductor includes a handle substrate 11 and a donor substrate bonded to a surface of the handle substrate 11 directly or through a bonding layer. The handle substrate 11 is composed of an insulating polycrystalline material, a surface 15 of the handle substrate 11 has a microscopic central line average surface roughness Ra of 5 nm or smaller, and recesses 6 are formed on the surface of the handle substrate.

Abstract: A composite substrate 10 includes a supporting substrate 12 and a piezoelectric substrate 14 which are bonded to each other. In this embodiment, the supporting substrate 12 and the piezoelectric substrate 14 are bonded to each other by an adhesive layer 16. In the composite substrate 10, since the supporting substrate 12 is composed of a translucent alumina ceramic, alignment is easily performed during FCB compared with the case where the supporting substrate is composed of an opaque ceramic. Furthermore, preferably, the linear transmittance and the total light transmittance from the front of the supporting substrate 12 in the visible light range (360 to 750 nm) are 10% or more and 70% or more, respectively.

Abstract: A composite wafer 10 includes a supporting substrate 12 and a semiconductor substrate 14 which are bonded to each other by direct bonding. The supporting substrate 12 is a translucent alumina substrate with an alumina purity of 99% or more. The linear transmittance of the supporting substrate 12 at the visible light range is 40% or less. Furthermore, the total light transmittance from the front at a wavelength of 200 to 250 nm of the supporting substrate 12 is 60% or more. The average crystal grain size of the supporting substrate 12 is 10 to 35 ?m. The semiconductor substrate 14 is a single crystal silicon substrate. Such a composite wafer 10 has insulation performance and thermal conduction comparable to those of a SOS wafer, can be manufactured at low cost, and can be easily made to have a large diameter.

Abstract: A composite wafer 10 includes a supporting substrate 12 and a semiconductor substrate 14 which are bonded to each other by direct bonding. The supporting substrate 12 is a translucent alumina substrate with an alumina purity of 99% or more. The linear transmittance of the supporting substrate 12 at the visible light range is 40% or less. Furthermore, the total light transmittance from the front at a wavelength of 200 to 250 nm of the supporting substrate 12 is 60% or more. The average crystal grain size of the supporting substrate 12 is 10 to ?m. The semiconductor substrate 14 is a single crystal silicon substrate. Such a composite wafer 10 has insulation performance and thermal conduction comparable to those of a SOS wafer, can be manufactured at low cost, and can be easily made to have a large diameter.

Abstract: An optical waveguide device includes a substrate of a ferroelectric material, at least a pair of electrodes 4A, 4B provided on one main face of the substrate, and a channel-type optical waveguide 5A formed in a gap 1 of the pair of the electrodes. The optical waveguide 5A has a curved part 15. A central line C of the gap 1 is provided outside of a center line WC of the optical waveguide with respect to the center O of curvature of the curved part 15.

Abstract: The invention provides an optical phase modulator having a substrate made of an electro-optical material, a signal electrode provided on the substrate and first and second ground electrodes provided on both sides of the signal electrode. The electrodes are provided so that a size of the first gap between the first ground electrode and the signal electrode is smaller than a size of a second gap between the second ground electrode and the signal electrode. Furthermore, an optical waveguide is provided in the first gap as an optical phase modulator and not provided in the second gap. A driving voltage required for the phase adjustments is thereby lowered, the impedance matching is easily made and excellent radio frequency property can be realized.

Abstract: An optical waveguide device includes a substrate of a ferroelectric material, at least a pair of electrodes 4A, 4B provided on one main face of the substrate, and a channel-type optical waveguide 5A formed in a gap 1 of the pair of the electrodes. The optical waveguide 5A has a curved part 15. A central line C of the gap 1 is provided outside of a center line WC of the optical waveguide with respect to the center O of curvature of the curved part 15.

Abstract: An optical modulator having an optical modulation part and a connection part for an optical fiber propagating light. The optical modulation part has a modulation substrate of an electro-optic material, a modulation optical waveguide formed on the modulation substrate, a high frequency interaction part for applying a voltage to the modulation optical waveguide to modulate the propagation of light, a first supporting substrate and a first adhesion layer for adhering the modulation substrate to the first supporting substrate. The connection part has a connection substrate of an electro-optic material, a connection optical waveguide formed on the connection substrate, a second supporting substrate, and a second adhesion layer for adhering the connection substrate to the second supporting substrate. The modulation substrate is adhered to the connection substrate. The first supporting substrate is adhered to the second supporting substrate.

Abstract: An optical modulator has an optical waveguide substrate having a pair of principal surfaces, a pair of side surfaces an incident face and exit face of light, the substrate being composed of a ferroelectric material; a channel optical waveguide having at least a pair of branch sections, a multiplexing section of the branch sections and an exit section provided on the downstream of the multiplexing section, the waveguide being formed on the principal surface of the optical waveguide substrate; a modulation electrode electrodes for applying a signal voltage for modulating light propagating in the branch sections; and a reflective groove for reflecting leaked light of off-mode emitted from the multiplexing section and emitting the light from a principal surface of the optical waveguide substrate. An operating point of the optical modulator is controlled by changing a DC bias applied on the modulation electrode based on optical output of the leaked light of off-mode.

Abstract: The invention provides an optical phase modulator having a substrate made of an electro-optical material, a signal electrode provided on the substrate and first and second ground electrodes provided on both sides of the signal electrode. The electrodes are provided so that a size of the first gap between the first ground electrode and the signal electrode is smaller than a size of a second gap between the second ground electrode and the signal electrode. Furthermore, an optical waveguide is provided in the first gap as an optical phase modulator and not provided in the second gap. A driving voltage required for the phase adjustments is thereby lowered, the impedance matching is easily made and excellent radio frequency property can be realized.

Abstract: An optical modulator having an optical modulation part and a connection part for an optical fiber propagating light. The optical modulation part has a modulation substrate of an electro-optic material, a modulation optical waveguide formed on the modulation substrate, a high frequency interaction part for applying a voltage to the modulation optical waveguide to modulate the propagation of light, a first supporting substrate and a first adhesion layer for adhering the modulation substrate to the first supporting substrate. The connection part has a connection substrate of an electro-optic material, a connection optical waveguide formed on the connection substrate, a second supporting substrate, and a second adhesion layer for adhering the connection substrate to the second supporting substrate. The modulation substrate is adhered to the connection substrate. The first supporting substrate is adhered to the second supporting substrate.

Abstract: An optical modulator 20 has an optical waveguide substrate 1 having a pair of principal surfaces 1a, 1c, a pair of side surfaces 1b and an incident face 1d and exit face 1e of light, the substrate being composed of a ferroelectric material; a channel optical waveguide 4 having at least a pair of branch sections 4b, a multiplexing section 6 of the branch sections and an exit section 4c provided on the downstream of the multiplexing section, the waveguide being formed on the principal surface 1a; a modulation electrode 2, 3 for applying a signal voltage for modulating light propagating in the branch sections; and a reflective groove 7 for reflecting leaked light of off-mode emitted from the multiplexing section 6 and emitting the light from the one principal surface 1a. An operating point of the optical modulator is controlled by changing a DC bias applied on the modulation electrode based on optical output of the leaked light of off-mode.

Abstract: An optical device includes an optical fiber mount with an optical fiber disposed thereon, and an optical demultiplexer having a slit defined in the optical fiber across an optical axis thereof, and an optical demultiplexing member inserted in the slit for demultiplexing a portion of an optical signal beam transmitted through the optical fiber, wherein the optical demultiplexer guides a demultiplexed optical signal beam from the optical demultiplexing member out of the optical fiber, an optical path changer for changing an optical path of the demultiplexed optical signal beam guided out of the optical fiber, a waveguide serving as a medium from which the demultiplexed optical signal beam is emitted to the optical path changer, and a filter disposed on a surface of the waveguide.

Abstract: An optical device has an optical fiber, an optical demultiplexer having an optical demultiplexing member for demultiplexing a portion of an optical signal beam transmitted through the optical fiber, as a demultiplexed optical signal beam, and guiding the demultiplexed optical signal beam out of the optical fiber, an optical path changer for changing an optical path of the demultiplexed optical signal beam guided out of the optical fiber, a waveguide serving as at least a medium from which the demultiplexed optical signal beam is emitted to the optical path changer, and a filter disposed on a surface of the waveguide. An angle of incidence of the demultiplexed optical signal beam on the filter is equal to or greater than 0.5°.