Abstract: A semiconductor laser device comprises a stem serving as a base; a laser diode LD submount having surface electrodes arranged thereon and joined to the surface of the stem; an LD chip joined to the surface electrode and connected with the surface electrode; and leads fixed in through holes formed in the stem by means of sealing parts and electrically connected to the surface electrodes via embedded layers in via holes formed in the LD submount, wherein grooves are formed in portions of the sealing parts or in portions of the LD submount around the connections between the leads and the embedded layers, to obtain a good modulated light waveform.

Abstract: A semiconductor laser device comprises a stem serving as a base; a laser diode LD submount having surface electrodes arranged thereon and joined to the surface of the stem; an LD chip joined to the surface electrode and connected with the surface electrode; and leads fixed in through holes formed in the stem by means of sealing parts and electrically connected to the surface electrodes via embedded layers in via holes formed in the LD submount, wherein grooves are formed in portions of the sealing parts or in portions of the LD submount around the connections between the leads and the embedded layers, to obtain a good modulated light waveform.

Abstract: The present application is provided with: a ridge laminated with a first conductivity type cladding layer, an active layer, and a second conductivity type first cladding layer in order and having a top portion formed to be flat; a first buried layer buried on both side areas of the ridge; a second buried layer covering the first buried layer and protruding toward the center of the ridge and toward a top portion of the ridge to form an opening formed by protruding portions facing each other; and a second conductivity type second cladding layer buried on the second buried layer and in the opening, wherein a surface of the second buried layer on a side to the top portion of the ridge is formed so as to fit within a surface of the second conductivity type first cladding layer.

Abstract: In a semiconductor laser device a dual wavelength semiconductor laser chip is joined onto a submount, junction down, to reduce built-in stress produced between the laser chip and the submount and to decrease polarization angles of the two respective lasers. SnAg solder is used to join the dual wavelength semiconductor laser chip onto the submount. When joining, with respect to each of the two lasers, a ratio of a distance between the center line of a waveguide and an end, placed at a lateral side of the laser chip, of a portion joining the laser chip and the submount, to a distance between the center line of the waveguide and another end, placed toward the center of the laser chip, of the portion joining the laser chip and the submount, falls within a range of 0.69 to 1.46.

Abstract: A semiconductor laser having a double channel ridge structure includes: a ridge; channel portions located on opposite sides of the ridge, sandwiching the ridge, and having an equivalent refractive index lower than the equivalent refractive index of the ridge; and layers defining outside surfaces of the channel portions and, having an equivalent refractive index higher than the equivalent refractive index of the channel portions. The ridge has a flare ridge structure with a width that is widened toward a light outgoing end surface, and the width of the channel portions where the width of the ridge is the narrowest is wider than the channel portions at the light outgoing end surface.

Abstract: A semiconductor laser having a double channel ridge structure includes: a ridge; channel portions located on opposite sides of the ridge, sandwiching the ridge, and having an equivalent refractive index lower than the equivalent refractive index of the ridge; and layers defining outside surfaces of the channel portions and, having an equivalent refractive index higher than the equivalent refractive index of the channel portions. The ridge has a flare ridge structure with a width that is widened toward a light outgoing end surface, and the width of the channel portions where the width of the ridge is the narrowest is wider than the channel portions at the light outgoing end surface.

Abstract: A semiconductor laser element including a ridge extending along a laser output direction of the laser element. The ridge has a central portion, two peripheral portions sandwiching the central portion, and two transitional portions. Window regions that are non-gain regions are located in corresponding peripheral portions. A difference in an equivalent refractive index between the central portion of the ridge and the peripheral portions on both sides is larger than a difference in an equivalent refractive index between the central portion of the ridge and transitional portions on both sides of the central portion in a gain region.

Abstract: A method of producing a semiconductor laser element including a step of growing a lower cladding layer, an active layer, a left upper cladding layer, a etching stopper layer having a multiple quantum well structure, an upper cladding layer and a contact layer in the order on a semiconductor substrate to form a laminate structure, a step of doping an impurity end portions near to edge surfaces of the laminate structure so as to cross over the active layer to form window regions and to make the etching stopper layer of window regions into disorder, a step of etching the contact layer in the window regions, a step of forming a protective film to form a ridge, and a step of etching both sides of the protective film with the protective film so as to cross over the disordered etching stopper layer.

Abstract: A method of producing a semiconductor laser element including, growing a lower cladding layer, an active layer, a first left upper cladding layer, a first etching stopper layer, a second left upper cladding layer, a second etching stopper layer, an upper cladding layer and a contact layer in the order on a semiconductor substrate to form a laminate structure, doping an impurity end portions near to edge surfaces of the laminate structure so as to cross over the active layer to form window regions, etching the contact layer in the window regions, forming a protective film to form a ridge, etching both sides of the protective film with the protective film at a condition which is set to etch the window regions up to a middle of the second left cladding layer and to etch the other region up to a middle of the upper cladding layer a step of wet etching the window regions up to the first etching stopper layer and the other region up to the second etching stopper layer.

Abstract: A semiconductor laser element including a ridge extending along a laser output direction of the laser element. The ridge has a central portion, two peripheral portions sandwiching the central portion, and two transitional portions. Window regions that are non-gain regions are located in corresponding peripheral portions. A difference in an equivalent refractive index between the central portion of the ridge and the peripheral portions on both sides is larger than a difference in an equivalent refractive index between the central portion of the ridge and transitional portions on both sides of the central portion in a gain region.

Abstract: An automobile mat which overcomes the border which divides the sound absorption or interruption function of the floor mat, wherein the mat absorbs or interrupts sound effectively and reduces the noise in the interior of the automobile. The mat comprises a backing cloth having an upper and lower face; a pile layer formed on said upper face of the backing cloth; a felt layer adhered to the lower face of the backing cloth and a top face of a foam latex layer; and the foam latex layer having the top and a bottom face adhered to the bottom face of the felt layer.

Abstract: To provide a semiconductor laser element having a structure capable of suppressing generation of a kink even in a case where an FFPx is made large, the semiconductor laser element has a ridge structure in which an active layer is provided between a semiconductor layer of one conductivity type and a semiconductor layer of the other conductivity type having a ridge, and window regions that are non-gain regions are provided at both ends thereof, wherein a difference in equivalent refractive index between the ridge and portions on both sides thereof in each of the window regions is larger than a difference in equivalent refractive index between the ridge and portions on both sides thereof in a gain region.

Abstract: An automobile mat which overcomes the border which divides the sound absorption or interruption function of the floor mat, wherein the mat absorbs or interrupts sound effectively and reduces the noise in the interior of the automobile. The mat comprises a backing cloth having an upper and lower face; a pile layer formed on said upper face of the backing cloth; a felt layer adhered to the lower face of the backing cloth and a top face of a foam latex layer; and the foam latex layer having the top and a bottom face adhered to the bottom face of the felt layer.

Abstract: In a semiconductor laser which is modulation-doped in an active layer having a multiple quantum well structure, emission efficiency and modulation-band are improved. A semiconductor laser has an active layer between a p-type cladding layer and an n-type cladding layer. The active layer has multiple quantum wells with a plurality of barrier layers and well layers, and at least one barrier layer is p-type modulation-doped. More specifically, quantity of p-type modulation-doping of a barrier layer close to the p-cladding layer is smaller than of a barrier layer close to the n-cladding layer. Therefore, differential gain and high-speed response can be improved while suppressing nonluminous recombination. Since the concentration of holes is high in a well layer distant from the p-type cladding layer, the nonuniformity of carrier concentration can also be reduced.

Abstract: In a semiconductor laser in which modulation-doping is performed to an active layer of a multiple quantum well structure, emission efficiency and a modulation-band are sufficiently improved. A semiconductor laser has an active layer formed between a p-type cladding layer and an n-type cladding layer. The active layer has multiple quantum wells with a plurality of barrier layers and well layers, and p-type modulation-doping is performed to at least one barrier layer. More specifically, a quantity of p-type modulation-dope of a barrier layer close to a p-cladding layer is smaller than that of a barrier layer close to an n-cladding layer. Therefore, a differential gain and high-speed response can be improved while suppressing nonluminous recombination. At the same time, since the concentration of holes is high in a well layer distant from the p-type cladding layer, the nonuniformity of carriers can also be improved.