Abstract: An optical branching/coupling device includes a single first port that has an optical fiber; a plurality of second ports each having an optical fiber and arranged at the periphery of the optical axis of the first port, in locations that are removed from the first port in an optical axis direction; a core layer that transmits light between the first port and the second ports; and a cladding layer that covers the periphery of the core layer, wherein the core includes a plurality of optical waveguides, one end side of the optical waveguides being connected to each core of the plurality of second ports, and another end side of the optical waveguides joining together and being connected to a core of the first port, and the optical waveguides are a cured product of a photocuring resin.

Abstract: A power converter includes: two switching elements; a positive electrode conductive plate: a negative electrode conductive plate; a mid-point conductive plate; a first heat sink; and a second heat sink. The positive electrode conductive plate is connected to a high-potential terminal of a series connection of the two switching elements, and the negative electrode conductive plate is connected to a low-potential terminal of the series connection. The mid-point conductive plate is connected to a middle point of the series connection. The first heat sink faces the positive electrode conductive plate and the negative electrode conductive plate with a first isolating layer interposed therebetween, and is connected to a ground terminal. The second heat sink faces the mid-point conductive plate with a second isolating layer interposed therebetween, and is isolated from the ground terminal.

Abstract: Provided is an optical branching/coupling device in which optical transmission quality is improved by preventing a reduction in optical transmission quality, the reduction being due, for example, to an optical waveguide core affecting a light of another optical waveguide core in the vicinity of a joining section of the two optical waveguide cores. This optical branching/coupling device includes: a first optical waveguide that is provided extending from one end side to other end side; a second optical waveguide that is provided extending on a separate route from the one end side to the other end side, the other end side of the second optical waveguide being joined to the other end side of the first optical waveguide; and a cladding layer that covers the periphery of the first optical waveguide and the second optical waveguide, wherein the first and second optical waveguides comprise a cured product of a photocuring resin.

Abstract: Provided is an optical branching/coupling device in which optical transmission quality is improved by preventing a reduction in optical transmission quality, the reduction being due, for example, to an optical waveguide core affecting a light of another optical waveguide core in the vicinity of a joining section of the two optical waveguide cores. This optical branching/coupling device includes: a first optical waveguide that is provided extending from one end side to other end side; a second optical waveguide that is provided extending on a separate route from the one end side to the other end side, the other end side of the second optical waveguide being joined to the other end side of the first optical waveguide; and a cladding layer that covers the periphery of the first optical waveguide and the second optical waveguide, wherein the first and second optical waveguides comprise a cured product of a photocuring resin.

Abstract: If the capacitance of a snubber capacitor, the inductance of a coil and the magnitude of a resistor are specified such that the resonance frequency of the snubber circuit coincides with the ringing frequency of the transistor, and the impedance of the first loop at the resonance frequency becomes smaller than the impedance of the second loop at the resonance frequency, a current component due to ringing flows in the snubber circuit, and energy is consumed by the resistor. Therefore, it is possible to quickly converge ringing.

Abstract: A power converter includes: two switching elements; a positive electrode conductive plate: a negative electrode conductive plate; a mid-point conductive plate; a first heat sink; and a second heat sink. The positive electrode conductive plate is connected to a high-potential terminal of a series connection of the two switching elements, and the negative electrode conductive plate is connected to a low-potential terminal of the series connection. The mid-point conductive plate is connected to a middle point of the series connection. The first heat sink faces the positive electrode conductive plate and the negative electrode conductive plate with a first isolating layer interposed therebetween, and is connected to a ground terminal. The second heat sink faces the mid-point conductive plate with a second isolating layer interposed therebetween, and is isolated from the ground terminal.

Abstract: If the capacitance of a snubber capacitor, the inductance of a coil and the magnitude of a resistor are specified such that the resonance frequency of the snubber circuit coincides with the ringing frequency of the transistor, and the impedance of the first loop at the resonance frequency becomes smaller than the impedance of the second loop at the resonance frequency, a current component due to ringing flows in the snubber circuit, and energy is consumed by the resistor. Therefore, it is possible to quickly converge ringing.

Abstract: An optical-fiber assembly, optical coupling device and optical-fiber coupling device provided with optical-fiber assembly. In the optical-fiber assembly, damaging a fixing material is prevented by preventing clad mode light from being incident on the fixing material and direct incidence, on the fixing material; of laser light emitted from a light-emitting element or an optical-fiber is prevented to generate resistance to the emitted light. The optical-fiber assembly constitutes by at least an optical-fiber and capillary. The optical-fiber is inserted into the capillary and one optical-fiber end is protruded outside the capillary. The optical-fiber outer periphery and capillary are fixed using fixing material and ceramic material disposed to be in contact with the entire optical-fiber outer circumference and have predetermined contact length in the optical-fiber axial direction.

Abstract: An optical-fiber assembly, optical coupling device and optical-fiber coupling device provided with optical-fiber assembly. In the optical-fiber assembly, damaging a fixing material is prevented by preventing clad mode light from being incident on the fixing material and direct incidence, on the fixing material; of laser light emitted from a light-emitting element or an optical-fiber is prevented to generate resistance to the emitted light. The optical-fiber assembly constitutes by at least an optical-fiber and capillary. The optical-fiber is inserted into the capillary and one optical-fiber end is protruded outside the capillary. The optical-fiber outer periphery and capillary are fixed using fixing material and ceramic material disposed to be in contact with the entire optical-fiber outer circumference and have predetermined contact length in the optical-fiber axial direction.

Abstract: An art of measuring a current with a suppressed influence of a switching noise is provided. The art disclosed by the present specification is a current sensor that measures an output current of a switching circuit. The current sensor is equipped with a magneto-optical element that is arranged at a current measurement point, a light source that radiates light onto the magneto-optical element, and a light receiver that receives transmitted light or reflected light of the magneto-optical element. The light source radiates light in synchronization with a carrier signal of the switching circuit. Light is radiated in synchronization with the carrier signal, and a current is measured with the aid of the light. Due to synchronization with the carrier signal, the current can be measured at timings other than a switching timing resulting from a PWM signal that is generated on the basis of the carrier signal.