Abstract: A semiconductor laser device that outputs light while periodically varying the temperature of a semiconductor laser, an optical waveguide, or a diffraction grating, outputs light while causing the optical waveguide or the diffraction grating to mechanically and periodically vary, or causes return light, which varies periodically or non-periodically, to be incident on the semiconductor laser. Since the periodical fluctuation is applied to the temperature of the semiconductor laser, the optical waveguide, or diffraction grating, the periodical mechanical variation is applied to the optical waveguide or the diffraction grating, or the return light is caused to be incident on the semiconductor laser, the semiconductor laser carries out a multimode oscillation from a low output to a high output without shifting between a single mode oscillation and a multimode oscillation.

Abstract: A semiconductor laser device according to the present invention outputs light while periodically varying the temperature of a semiconductor laser, an optical waveguide, or a diffraction grating, outputs light while causing the optical waveguide or the diffraction grating to mechanically and periodically vary, or causes return light, which varies periodically or non-periodically, to be incident on the semiconductor laser. Since the periodical fluctuation is applied to the temperature of the semiconductor laser, the optical waveguide, or diffraction grating, the periodical mechanical variation is applied to the optical waveguide or the diffraction grating, or the return light is caused to be incident on the semiconductor laser, the semiconductor laser carries out a multimode oscillation from a low output to a high output without shifting between a single mode oscillation and a multimode oscillation.

Abstract: A semiconductor laser device according to the present invention outputs light while periodically varying the temperature of a semiconductor laser, an optical waveguide, or a diffraction grating, outputs light while causing the optical waveguide or the diffraction grating to mechanically and periodically vary, or causes return light, which varies periodically or non-periodically, to be incident on the semiconductor laser. Since the periodical fluctuation is applied to the temperature of the semiconductor laser, the optical waveguide, or diffraction grating, the periodical mechanical variation is applied to the optical waveguide or the diffraction grating, or the return light is caused to be incident on the semiconductor laser, the semiconductor laser carries out a multimode oscillation from a low output to a high output without shifting between a single mode oscillation and a multimode oscillation.

Abstract: A vertical-cavity surface-emitting semiconductor laser has a substrate, a lower DBR structure portion having a plurality of layers provided on the substrate, a semiconductor buried structure portion provided over the lower DBR structure portion having at least one layer with buried therein an active layer, and an upper DBR structure portion having a plurality of layers provided over the semiconductor buried structure portion including the active layer. The active layer, at least one layer arranged over the active layer and at least one layer arranged beneath the active layer constitute an optical resonator region and each of the layers constituting the optical resonator region has an effective refractive index higher than respective effective refractive indices of other layers in the upper and lower DBR structure portions and a refractive index of the at least one layer constituting the semiconductor buried structure portion.

Abstract: A technique for electrically mounting a surface-normal optical device or material on a waveguide-type optical device while the characteristics of the mounted device are effectively used is disclosed. The waveguide-type optical device comprises a substrate on which optical waveguides or fibers are provided and a trench is formed; a pair of electrodes which is assigned to each optical waveguide or fiber and is formed from the surface of the substrate to wall surfaces of the trench; and a material or device which is filled or inserted into the trench, and which has an electro-optic effect, thermo-optic effect, light emitting function, light receiving function, or light modulating function. Another type of device comprises a thin and surface-normal active optical device driven by an applied voltage, which is substantially vertically inserted into the trench and is fixed in the trench; and a support member attached to the inserted device.

Abstract: A vertical-cavity surface-emitting semiconductor laser has a substrate, a lower DBR structure portion having a plurality of layers provided on the substrate, a semiconductor buried structure portion provided over the lower DBR structure portion having at least one layer with buried therein an active layer, and an upper DBR structure portion having a plurality of layers provided over the semiconductor buried structure portion comprising the active layer. The active layer, at least one layer arranged over the active layer and at least one layer arranged beneath the active layer constitute an optical resonator region and each of the layers constituting the optical resonator region has an effective refractive index higher than respective effective refractive indices of other layers in the upper and lower DBR structure portions and a refractive index of the at least one layer constituting the semiconductor buried structure portion.

Abstract: A vertical-cavity surface-emitting semiconductor laser has a substrate, a lower DBR structure portion having a plurality of layers provided on the substrate, a semiconductor buried structure portion provided over the lower DBR structure portion having at least one layer with buried therein an active layer, and an upper DBR structure portion having a plurality of layers provided over the semiconductor buried structure portion comprising the active layer. The active layer, at least one layer arranged over the active layer and at least one layer arranged beneath the active layer constitute an optical resonator region and each of the layers constituting the optical resonator region has an effective refractive index higher than respective effective refractive indices of other layers in the upper and lower DBR structure portions and a refractive index of the at least one layer constituting the semiconductor buried structure portion.

Abstract: A technique for electrically mounting a surface-normal optical device or material on a waveguide-type optical device while the characteristics of the mounted device are effectively used is disclosed. The waveguide-type optical device comprises a substrate on which optical waveguides or fibers are provided and a trench is formed; a pair of electrodes which is assigned to each optical waveguide or fiber and is formed from the surface of the substrate to wall surfaces of the trench; and a material or device which is filled or inserted into the trench, and which has an electro-optic effect, thermo-optic effect, light emitting function, light receiving function, or light modulating function. Another type of device comprises a thin and surface-normal active optical device driven by an applied voltage, which is substantially vertically inserted into the trench and is fixed in the trench; and a support member attached to the inserted device.

Abstract: A vertical-cavity surface-emitting semiconductor laser has first and second semiconductor multi-layered films, an active layer, and third and fourth semiconductor multi-layered films which are piled up on a GaAs substrate in that order. Furthermore, the first film is formed by piling up Al.sub.x-1 Ga.sub.1-x1 As layers (0.ltoreq.x1.ltoreq.1) and Al.sub.x2 Ga.sub.1-x2 As layers (0.ltoreq.x2.ltoreq.1) one after the other by turns. The second film is formed by piling up In.sub.x3 Ga.sub.1-x3 As.sub.y3 P.sub.1-y3 layers (0.ltoreq.x3, y3.ltoreq.1) and In.sub.x4 Ga.sub.1-x4 As.sub.y4 P.sub.1-y4 layers (0.ltoreq.x4, y4.ltoreq.1) one after the other by turns. The active layer is provided as an In.sub.x5 Ga.sub.1-x5 As.sub.y5 P.sub.1-y5 layer (0.ltoreq.x5, y5.ltoreq.1). The third film is formed by piling up In.sub.x6 Ga.sub.1-x6 As.sub.y6 P.sub.1-y6 layers (0.ltoreq.x6, y6.ltoreq.1) and In.sub.x7 Ga.sub.1-x7 As.sub.y7 P.sub.1-y7 layers (0.ltoreq.x7, y7.ltoreq.1) one after the other by turns.

Abstract: A vertical-cavity surface-emitting semiconductor laser has first and second semiconductor multi-layered films, an active layer, and third and fourth semiconductor multi-layered films which are piled up on a GaAs substrate in that order. Furthermore, the first film is formed by piling up Al.sub.x1 Ga.sub.1-x1 As layers (0.ltoreq.x1.ltoreq.1) and Al.sub.x2 Ga.sub.1-x2 As layers (0.ltoreq.x2.ltoreq.1) one after the other by turns. The second film is formed by piling up In.sub.x3 Ga.sub.1-x3 As.sub.y3 P.sub.1-y3 layers (0.ltoreq.x3, y3.ltoreq.1) and In.sub.x4 Ga.sub.1-x4 As.sub.y4 P.sub.1-y4 layers (0.ltoreq.x4, y4.ltoreq.1) one after the other by turns. The active layer is provided as an In.sub.x5 Ga.sub.1-x5 As.sub.y5 P.sub.1-y5 layer (0.ltoreq.x5, y5.ltoreq.1). The third film is formed by piling up In.sub.x6 Ga.sub.1-x6 AS.sub.y6 P.sub.1-y6 layers (0.ltoreq.x6, y6.ltoreq.1) and In.sub.x7 Ga.sub.1-x7 As.sub.y7 P.sub.1-y7 layers (0.ltoreq.x7, y7.ltoreq.1) one after the other by turns.

Abstract: An optical gate array includes a photodetector, an optical modulator, and a reflecting structure arranged therebetween. The photodetector, the optical modulator, and the reflecting structure are composed of semiconductor materials. The photodetector includes an MQW (Multi Quantum Well). The reflecting structure is constituted by a distributed Bragg reflector formed by alternately stacking semiconductor layers having different refractivities. The photodetector and the optical modulator are arranged to receive light from different directions. The modulation characteristics of the optical modulator are controlled by the intensity of light radiated on the photodetector. The reflecting structure connects the photodetector and the modulator electrically and isolates lights radiated on both parts. A plurality of optical gates, each constituted by the photodetector, the optical modulator, and the reflection structure, are two-dimensionally arranged.

Abstract: A core for photographic light-sensitive material use made of wooden source material which can be recycled or decomposed in natural environment is disclosed. The core center is made of paper covered with a buffer layer made of 100% wooden pulp having a density of not more than 0.1 g/cm.sup.3. The buffer layer is covered with a reinforcing sheet made of paper with a tensile strength of 0.3 kg/15 mm width or more.