Abstract: A light-emitting element includes: a substrate; a semiconductor chip, formed over the substrate, that includes a plurality of semiconductor layers; a first protective film formed on a first end face of the semiconductor chip that includes a luminous point from which light is emitted; and a first light-absorbing film formed on a part of a surface of the first protective film. The first light-absorbing film covers a part of the surface of the first protective film excluding a portion of the surface through which light emitted from the luminous point passes.

Abstract: Provided is an imaging device capable of improving imaging accuracy while suppressing increase in a size of the device and cost thereof. An imaging device includes: a light source which is a semiconductor laser that radiates infrared light to an imaging target; a polarizing filter that blocks light that is reflected by a surface of the imaging target and transmits light that is reflected inside the imaging target; and an image sensor that receives the light that is transmitted through the polarizing filter and captures an image of the imaging target.

Abstract: A semiconductor laser element is provided with: a substrate formed of a semiconductor; a semiconductor laminated film, which is laminated on the substrate, and which includes an active layer; a first electrode and a second electrode, which are provided on surfaces parallel to the active layer on the side where the semiconductor laminated film is formed on the substrate; and a facet protection film that is provided on both the facets, which are perpendicular to the active layer, and which face each other. In the semiconductor laser element, the facet is used as a fixing surface for the semiconductor laser element, said facet having the facet protection film formed thereon.

Abstract: A semiconductor laser element is provided with: a substrate formed of a semiconductor; a semiconductor laminated film, which is laminated on the substrate, and which includes an active layer; a first electrode and a second electrode, which are provided on surfaces parallel to the active layer on the side where the semiconductor laminated film is formed on the substrate; and a facet protection film that is provided on both the facets, which are perpendicular to the active layer, and which face each other. In the semiconductor laser element, the facet is used as a fixing surface for the semiconductor laser element, said facet having the facet protection film formed thereon.

Abstract: In a semiconductor laser device including a semiconductor laser element that emits laser light from an emission region thereof, a cap having a peripheral wall and a ceiling wall that cover the semiconductor laser element and having a window portion formed in the ceiling wall to face the emission region, and a transparent optical member that fills the window portion, the optical member is formed by curing a liquid resin and holds the ceiling wall, and a light incidence surface of the optical member faces the emission region and is formed by natural flow of the liquid resin.

Abstract: Provided is a semiconductor laser chip improved more in heat dissipation performance. This semiconductor laser chip includes a substrate, which has a front surface and a rear surface, nitride semiconductor layers, which are formed on the front surface of the substrate, an optical waveguide (ridge portion), which is formed in the nitride semiconductor layers, an n-side electrode, which is formed on the rear surface of the substrate, and notched portions, which are formed in regions that include the substrate to run along the optical waveguide (ridge portion). The notched portions have notched surfaces on which a metal layer connected to the n-side electrode is formed.

Abstract: Provided is a semiconductor laser chip improved more in heat dissipation performance. This semiconductor laser chip includes a substrate, which has a front surface and a rear surface, nitride semiconductor layers, which are formed on the front surface of the substrate, an optical waveguide (ridge portion), which is formed in the nitride semiconductor layers, an n-side electrode, which is formed on the rear surface of the substrate, and notched portions, which are formed in regions that include the substrate to run along the optical waveguide (ridge portion). The notched portions have notched surfaces on which a metal layer connected to the n-side electrode is formed.

Abstract: A semiconductor laser device has a semiconductor laser and a polarizing diffraction grating that is arranged ahead of the semiconductor laser. A reflected light from an optical recording medium is diffracted by the polarizing diffraction grating according to the polarization direction of the reflected light. The reflected light is thereby deviated from the direction toward the semiconductor laser to prevent the reflected light from returning to the semiconductor laser.

Abstract: A semiconductor laser device has a laser chip and a submount therefor. The submount has a fore end surface inclined in a direction of thickness of the submount. The laser chip is mounted on the submount in such a manner that an edge line of the fore end surface is perpendicular to a light emission axis of the laser chip, and that a light-emitting end surface of the laser chip projects from the edge line by a projection length in the direction of the light emission axis of the laser chip. Thereby, the laser chip receiving no return light is easily positioned with high accuracy.

Abstract: A semiconductor laser device has a semiconductor laser and a polarizing diffraction grating that is arranged ahead of the semiconductor laser. A reflected light from an optical recording medium is diffracted by the polarizing diffraction grating according to the polarization direction of the reflected light. The reflected light is thereby deviated from the direction toward the semiconductor laser to prevent the reflected light from returning to the semiconductor laser.

Abstract: A semiconductor laser chip has an emission point on a PN junction thereof. The emission point is located at a distance of 80 &mgr;m or less along the PN junction from a lateral side surface of the semiconductor laser chip.

Abstract: First, second semiconductor lasers and a photodetector are integrated in a laser package of an integrated laser unit. A composite PBS is so structured that generally 100% of s-polarized light derived from the first semiconductor laser is reflected while generally 100% of s-polarized light derived from the second semiconductor laser is transmitted. Then, return beams of s-polarized light of the first, second semiconductor lasers separated by the composite PBS 18 are converged on the same photodetector by the first, second polarization hologram devices. By doing so, the first, second polarization hologram devices are adjusted independently of each other, so that the offset adjustment of servo error signals for the first, second semiconductor lasers can be easily achieved in assembly process. Thus, the optical pickup becomes easy to assemble and adjust.

Abstract: A semiconductor laser device has a laser chip and a submount therefor. The submount has a fore end surface inclined in a direction of thickness of the submount. The laser chip is mounted on the submount in such a manner that an edge line of the fore end surface is perpendicular to a light emission axis of the laser chip, and that a light-emitting end surface of the laser chip projects from the edge line by a projection length in the direction of the light emission axis of the laser chip.

Abstract: A semiconductor laser chip has an emission point on a PN junction thereof. The emission point is located at a distance of 80 &mgr;m or less along the PN junction from a lateral side surface of the semiconductor laser chip.