Abstract:
An optical device includes: a substrate; an optical branching filter on the substrate and dividing input light into first and second input lights; first and second Mach-Zehnder optical modulators on the substrate and respectively modulating the first and second input lights; and an optical coupler on the substrate and combining light modulated by the first Mach-Zehnder optical modulator and light modulated by the second Mach-Zehnder optical modulator. Each of the first and second Mach-Zehnder optical modulator includes two optical waveguides, a phase modulation electrode applying a modulation voltage across the optical waveguides to change phases of light in the optical waveguides, and a feed line and a terminal line respectively connected to opposite ends of the phase modulation electrode to supply the modulation voltage to the phase modulation electrode. The feed lines and the terminal lines respectively extend to peripheral portions of the substrate.
Abstract:
A simple silicone-rubber bonded object is provided in which non-flowable substrates, i.e., a three-dimensional silicone rubber elastic substrate molded beforehand and an adherend substrate, were able to be tenaciously bonded to each other without using a flowable curable adhesive or pressure-sensitive adhesive and which is inexpensive and has high productivity. The silicone-rubber bonded object comprises a three-dimensional silicone rubber elastic substrate having hydroxyl groups on the surface and an adherend substrate having hydroxyl groups on the surface, the substrates having been laminated to each other through covalent bonding between the hydroxyl groups of both. The elastic substrate and/or the adherend substrate has undergone corona discharge treatment and/or plasma treatment, whereby the hydroxyl groups have been formed on the surface thereof.
Abstract:
A semiconductor optical element has an active layer including quantum dots. The density of quantum dots in the resonator direction in a portion of the active layer in which the density of photons is relatively high is increased relative to the density of quantum dots in a portion of the active layer in which the density of photons is relatively low.
Abstract:
A semiconductor laser according to the present invention comprises: a substrate; an n-cladding layer disposed on the substrate; an active layer disposed on the n-cladding layer; a p-cladding layer disposed on the active layer and forming a waveguide ridge; and a diffraction grating layer disposed between the active layer and the n-cladding layer or the p-cladding layer and including a phase shift structure in a part of the diffraction grating layer in an optical waveguide direction. The width of the p-cladding layer is increased in a portion corresponding to the phase shift structure of the diffraction grating layer.
Abstract:
A semiconductor laser according to the present invention comprises: a substrate; an n-cladding layer disposed on the substrate; an active layer disposed on the n-cladding layer; a p-cladding layer disposed on the active layer and forming a waveguide ridge; and a diffraction grating layer disposed between the active layer and the n-cladding layer or the p-cladding layer and including a phase shift structure in a part of the diffraction grating layer in an optical waveguide direction. The width of the p-cladding layer is increased in a portion corresponding to the phase shift structure of the diffraction grating layer.
Abstract:
Input light is split by an input-light splitter into first split light and second split light. A multiplex-interference portion performs multiplex interference of the first split light and the second split light to generate intensity-modulated light having a first wavelength. A phase modulation portion is fed with the intensity-modulated light and continuous wave light having a wavelength equal to a second wavelength, and performs cross-phase modulation of the continuous wave light in accordance with phase modulation of the input light.
Abstract:
A semiconductor laser device according to the present invention comprises an optical waveguide laminated structure having: a first first-cladding layer made up of a p-InP layer; a double heterojunction layer of p-AlGaInAs; a second first-cladding layer made up of a p-InP layer; a first light confining layer of p-InGaAsP; an active layer of InGaAsP having a quantum well structure; a second light confining layer of n-InGaAsP; and a second-cladding layer made up of an n-InP layer, and heterojunctions of the second kind are formed at the interfaces between the first first-cladding layer and the double heterojunction layer and between the double heterojunction layer and the second first-cladding layer.
Abstract:
A dielectric sheet is attached to the inner surface of the portable telephone housing. The dielectric sheet extends in the area between the user's head and a whip antenna of the portable telephone. The real part and the imaginary part of the relative dielectric constant of the dielectric sheet is properly selected such that the dielectric sheet can reduce SAR (Specific Absorption Rate) and improve antenna efficiency.
Abstract:
An electroabsorption semiconductor optical modulator includes a light absorption layer for generating a modulated light beam by absorbing an incident light beam. A well layer in the light absorption layer, accumulates charge carriers generated by the light absorption layer. The charge carriers are guided and released from the well layer upon receipt of an incident excitation light beam having a wavelength corresponding to the bandgap energy of the well layer. The incident light beam is modulated by changes in absorption coefficient in response to an externally applied voltage. The modulator responds to a high-intensity incident light beam at high frequency, free from deterioration of extinction characteristics, and has good transmission characteristics.
Abstract:
A semiconductor device has a first semiconductor layer, a second semiconductor layer, and an active layer sandwiched between the first and the second semiconductor layer and emits light from the active layer when a voltage is applied across the first and the second semiconductor layer. The semiconductor device includes an anode on the first semiconductor layer, an insulating film on the anode, and a screen electrode on the insulating film covering at least part of the anode. The second semiconductor layer is grounded and the screen electrode is electrically connected to the grounded second semiconductor layer. The screen electrode screens the anode to prevent flow of a leakage current between the first and second semiconductor layers due to electromagnetic waves.