Abstract: A multi-layered dielectric film that is coated on the end surfaces or other surfaces of optical products, wherein said multi-layered dielectric film is composed of alternate layers consisting of two kinds of dielectric layer, one of which is a first dielectric layer of TiO.sub.2 or ZnS with a high refractive index n.sub.1 and the other of which is a second dielectric layer of Al.sub.2 O.sub.3 with a low refractive index n.sub.2.

Abstract: A semiconductor laser element of the present invention provides a double hetero junction structure having two clad layers and an active layer formed between the two clad layers. High resistance regions are formed vertically to the light propagating direction at almost the same interval as the light wavelength in at least one of the two clad layers. The high resistance regions form a periodic current blocking structure so the semiconductor laser element may oscillate in a single longitudinal mode even in a non-steady state operation.

Abstract: A semiconductor laser device comprising a semiconductor substrate, an active layer having a refractive index greater than that of said substrate and having an energy gap smaller than that of said substrate, and a cladding layer having a conductivity type different from that of said substrate, in that order, resulting in a double-heterostructure, wherein two parallel grooves with a given distance therebetween are disposed in the double-heterostructure so as to reach said substrate and a first burying layer having the same conductivity type as said substrate, a second burying layer having a conductivity type different from that of said substrate and a third burying layer having the same conductivity type as said substrate are disposed outside of the two grooves in that order, and moreover a semiconductor layer with the flat surface having a conductivity type different from that of said substrate is disposed over the third burying layer and the area positioned between the two parallel grooves.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operation area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A structure is described for covering slide legs of seat slides attached to a floor panel through openings which are formed in a floor carpet placed on the floor panel. Portions of the floor carpet which correspond to the slide legs attached to the floor panel are swelled upward to form cover portions each having a wall erected toward the seat slide. Each erected wall is cut off or cutting is applied to three sides of the erected wall at each of the cover sections, leaving one side thereof not cut so as to enable the erected wall portion to be folded downward along the uncut side onto the back face of the floor carpet. The bottom edges of both side faces of each of the cover portions are cut to open both side faces. These side faces are inserted under the back face of the floor carpet after the slide legs are attached to the floor panel.

Abstract: A semiconductor laser device comprises a laminated crystal structure which includes a Ga.sub.1-y Al.sub.y As optical guiding layer and a Ga.sub.1-z Al.sub.z As (z>y) cladding layer in this sequence, the cladding layer is formed on both a Ga.sub.1-x Al.sub.2 As (0.ltoreq.x.ltoreq.0.1 and x<y) layer and the optical guiding layer. The AlAs mole fraction y of the optical guiding layer is greater than 0.1.

Abstract: A semiconductor laser device comprising a double-heterostructure that is composed of an active layer and a pair of cladding layers sandwiching the active layer therebetween, and a stripe structure that is disposed on the double-heterostructure, the stripe structure being composed of a current blocking layer with a conductive type different from that of the adjacent cladding layer, and the current blocking layer having a striped groove constituting a current path, wherein the cladding layer that contacts the current blocking layer is composed of an In.sub.1-s Ga.sub.s P.sub.1-t As.sub.t crystal material (wherein 0.51.ltoreq.s.ltoreq.1, 0.ltoreq.t.ltoreq.1 and s=2.04t-1.04).

Abstract: An integrated optical disc pickup comprising an optical waveguide in the form of a insulation layer provided on the surface of a substrate, a semiconductor laser disposed outside the waveguide, a beam splitter of the transmission type and a Luneburg lens provided on the path of propagation of a laser beam from the semiconductor laser through the waveguide and arranged in the order mentioned in a direction away from the laser, a transmission grating provided on the path through the waveguide to be followed by the laser beam upon having its direction changed by the beam splitter after emanating from the laser, passing through the beam splitter and the Luneburg lens, being reflected from an optical disc disposed outside the waveguide and passing through the Luneburg lens, and first and second photodetectors disposed on the paths of propagation through the waveguide of two portions of the laser beam divided by the diffraction grating.

Abstract: A semiconductor laser device comprising an active layer, a layer furnished with a diffraction grating and formed in the vicinity of said active layer, and another layer formed on said layer with the diffraction grating and having a refractive index smaller than that of said active layer but greater than that of said layer with the diffraction grating.

Abstract: A distributed feedback semiconductor laser device comprising a laser oscillation region and a distributed reflector which are provided in a laminated crystal structure, and comprising facets at both the ends, wherein a light emitting face is disposed at one or both ends of the laser oscillation region, the face being parallel to the lamination direction and intersecting with the light emitting direction at an angle which is 90 degrees minus the Bresster angle.

Abstract: A method for the production of semiconductor devices comprising introducing source gases, etching gases or source molecules into a substrate to grow crystalline layers on said substrate or to etch said substrate, resulting in a semiconductor device, wherein said method further comprises applying a given electric potential to said substrate; applying an electric potential that is different from that of said substrate to an electron-beam irradiator disposed directly above said substrate; and irradiating said irradiator with electron beams from an electron-beam emitting means, whereby said substrate is irradiated with the secondary electron beams generated from said irradiator and/or with the electron beams transmitted through said irradiator.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A molding device for molding or shaping a plastically moldable sheet includes a lower mold having a recess which extends along an inner wall of the lower mold, an upper mold having a raised portion which is neatly received in the recess of the lower mold when the upper mold is properly seated on the lower mold to press the sheet, and a sheet mover including a rotatable member which is rotatably arranged on the outer wall of the lower mold and partially exposed to the recess of the lower mold.

Abstract: A distributed feedback semiconductor laser device with a resonator comprising a multi-layered optical waveguide that contains an optical guiding area with a periodic corrugation, the optical guiding area being composed of at least two regions, a first region I and a second region II, wherein both the periodicity of the corrugation and the depth of each concave portion of the corrugation of the first region I of the optical guiding area are the same as those of the second region II of the optical guiding area, and moreover the thickness of the first region I of the optical guiding area is the same as that of the second region II of the optical guiding area, so that the effective refractive index of the first region I in the resonator direction becomes the same as that of the second region II in the resonator direction and the Bragg wavelength is maintained at a fixed level in the the resonator direction; and there is a difference in their refractive index at the interface between the first and second regions o

Abstract: Disclosed is a medical vascular guide wire made of a synthetic resin hollow monofilament. The guide wire is comprised of a tip part, a flexible part having a smaller diameter than the other parts, a tapering part and a manipulating part, these four parts continuously forming in line, in that order, along the monofilament axis. At least the tip part and the manipulating part have X-ray impermeable material inserted in the respective hollows thereof. A self-guiding type catheter made of a synthetic resin, multi-hollow monofilament is also provided.