Abstract: An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration is provided. In a method of driving a laser diode, the laser diode is driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over.

Abstract: A laser diode capable of performing self-pulsation operation, and capable of sufficiently reducing the coherence of laser light and stably obtaining low-noise laser light is provided. A laser diode includes: a laser chip including at least one laser stripe which extends in a resonator length direction between a first end surface and a second end surface opposed to each other, in which the laser stripe includes a gain region and a saturable absorption region in the resonator length direction, and the width of the laser stripe in the saturable absorption region is larger than the width of the laser stripe in the gain region.

Abstract: Nitride semiconductor wafers which are produced by epitaxially grown nitride films on a foreign undersubstrate in vapor phase have strong inner stress due to misfit between the nitride and the undersubstrate material. A GaN wafer which has made by piling GaN films upon a GaAs undersubstrate in vapor phase and eliminating the GaAs undersubstrate bends upward due to the inner stress owing to the misfit of lattice constants between GaN and GaAs. Ordinary one-surface polishing having the steps of gluing a wafer with a surface on a flat disc, bringing another surface in contact with a lower turntable, pressing the disc, rotating the disc, revolving the turntable and whetting the lower surface, cannot remedy the inherent distortion. The Distortion worsens morphology of epitaxial wafers, lowers yield of via-mask exposure and invites cracks on surfaces. Nitride crystals are rigid but fragile. Chemical/mechanical polishing has been requested in vain.

Abstract: [PROBLEM TO BE SOLVED] A hemorrhoid ligation apparatus that allows the operator to handle with a single hand to ligate a hemorrhoid, under minimized risk of committing improper operation, is to be provided.

Abstract: An upper portion of a second clad layer and a contact layer are provided with grooves so as to form a ridge therebetween. An electrode is formed on the ridge. An insulation film is formed to extent on side surfaces of the ridge, on the inside of the grooves, and those portions of the contact layer which are located on the outside of the grooves. The thickness of those portions of the insulation film which are located on the contact layer in the areas on the outside of the grooves is set to be greater than at least the thickness of the electrode. Besides, a pad electrode is formed to cover the electrode and to extend on the insulation film on the upper side of the areas on the outside of the grooves. The upper surfaces of those portions of the pad electrode which are located on the upper side of the areas on the outside of the grooves are set to be above the upper surface of that portion of the pad electrode which is located on the upper side of the ridge.

Abstract: Nitride semiconductor wafers which are produced by epitaxially grown nitride films on a foreign undersubstrate in vapor phase have strong inner stress due to misfit between the nitride and the undersubstrate material. A GaN wafer which has made by piling GaN films upon a GaAs undersubstrate in vapor phase and eliminating the GaAs undersubstrate bends upward due to the inner stress owing to the misfit of lattice constants between GaN and GaAs. Ordinary one-surface polishing having the steps of gluing a wafer with a surface on a flat disc, bringing another surface in contact with a lower turntable, pressing the disc, rotating the disc, revolving the turntable and whetting the lower surface, cannot remedy the inherent distortion. The Distortion worsens morphology of epitaxial wafers, lowers yield of via-mask exposure and invites cracks on surfaces. Nitride crystals are rigid but fragile. Chemical/mechanical polishing has been requested in vain.

Abstract: A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.

Abstract: A medical device (1) includes a main body (2); a first piercing needle (4) provided slidably with respect to the main body (2); a first holding plate (61) adapted to hold the first piercing needle (4) and provided slidably on the main body (2); and a second holding plate (62) adapted to hold a second piercing needle (3) and detachably and movably mounted on the first holding plate (61), wherein the second holding plate (62) is mounted so as to move to the first holding plate (61) in a predetermined direction.

Abstract: A semiconductor light emitting device made of nitride III-V compound semiconductors includes an active layer made of a first nitride III-V compound semiconductor containing In and Ga, such as InGaN; an intermediate layer made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor, such as InGaN; and a cap layer made of a third nitride III-V compound semiconductor containing Al and Ga, such as p-type AlGaN, which are deposited in sequential contact.

Abstract: Provided is a GaN-based semiconductor light emitting device formed on a GaN single-crystal substrate and having a configuration capable of reducing a current leak. A GaN-based semiconductor laser device (50) is disclosed as an example of the GaN-based semiconductor light emitting device, and it is a semiconductor laser device having a structure such that a p-side electrode and an n-side electrode are provided on a multilayer structure of GaN-based compound semiconductor layers. The GaN-based semiconductor laser device (50) is similar in configuration to a conventional GaN-based semiconductor laser device formed on a sapphire substrate except that a GaN single-crystal substrate (52) is used in place of the sapphire substrate and that the multilayer structure is directly formed on the GaN single-crystal substrate (52) without providing a GaN-ELO structure layer. The GaN single-crystal substrate (52) has continuous belt-shaped core portions (52a) each having a width of 10 ?m.

Abstract: A semiconductor light emitting device made of nitride III-V compound semiconductors is includes an active layer made of a first nitride III-V compound semiconductor containing In and Ga, such as InGaN; an intermediate layer made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor, such as InGaN; and a cap layer made of a third nitride III-V compound semiconductor containing Al and Ga, such as p-type AlGaN, which are deposited in sequential contact.

Abstract: A semiconductor light emitting device made of nitride III-V compound semiconductors includes an active layer made of a first nitride III-V compound semiconductor containing In and Ga, such as InGaN; an intermediate layer made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor, such as InGaN; and a cap layer made of a third nitride III-V compound semiconductor containing Al and Ga, such as p-type AlGaN, which are deposited in sequential contact.

Abstract: A multi-beam semiconductor laser device capable of emitting respective laser beams with uniform optical output levels and enabling easy alignment is provided. This multi-beam semiconductor laser device (40) is a GaN base multi-beam semiconductor laser device provided with four laser stripes (42A, 42B, 42C and 42D) which are capable of emitting laser beams with the same wavelength. The respective laser oscillating regions (42A to 42D) are provided with a p-type common electrode (48) on a mesa structure (46) which is formed on a sapphire substrate (44), and have active regions (50A, 50B, 50C and 50D) respectively. Two n-type electrodes (52A and 52B) are provided on an n-type GaN contact layer (54) and located as common electrodes opposite to the p-type common electrode (48) on both sides of the mesa structure (46). The distance A between the laser stripe (42A) and the laser stripe (42D) is no larger than 100 ?m.

Abstract: A semiconductor light emitting device made of nitride III-V compound semiconductors includes an active layer made of a first nitride III-V compound semiconductor containing In and Ga, such as InGaN; an intermediate layer made of a second nitride III-V compound semiconductor containing In and Ga and different from the first nitride III-V compound semiconductor, such as InGaN; and a cap layer made of a third nitride III-V compound semiconductor containing Al and Ga, such as p-type AlGaN, which are deposited in sequential contact.

Abstract: In a semiconductor light emitting device such as a semiconductor laser using nitride III-V compound semiconductors and having a structure interposing an active layer between an n-side cladding layer and a p-side cladding layer, the p-side cladding layer is made of an undoped or n-type first layer 9 and a p-type second layer 12 that are deposited sequentially from nearer to remoter from the active layer. The first layer 9 is not thinner than 50 nm. The p-type second layer 12 includes a p-type third layer having a larger band gap inserted therein as an electron blocking layer. Thus the semiconductor light emitting device is reduced in operation voltage while keeping a thickness of the p-side cladding layer necessary for ensuring favorable optical properties.

Abstract: A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.

Abstract: Provided is a GaN-based semiconductor light emitting device formed on a GaN single-crystal substrate and having a configuration capable of reducing a current leak. A GaN-based semiconductor laser device (50) is disclosed as an example of the GaN-based semiconductor light emitting device, and it is a semiconductor laser device having a structure such that a p-side electrode and an n-side electrode are provided on a multilayer structure of GaN-based compound semiconductor layers. The GaN-based semiconductor laser device (50) is similar in configuration to a conventional GaN-based semiconductor laser device formed on a sapphire substrate except that a GaN single-crystal substrate (52) is used in place of the sapphire substrate and that the multilayer structure is directly formed on the GaN single-crystal substrate (52) without providing a GaN-ELO structure layer. The GaN single-crystal substrate (52) has continuous belt-shaped core portions (52a) each having a width of 10 ?m.

Abstract: A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.

Abstract: Provided is a method of manufacturing a semiconductor device, which is adapted to prevent the deposition of a material on a laser light emitting edge, thereby enabling an improvement in longevity characteristics of a laser. A base having a laser chip mounted thereon is irradiated with an energy beam having a shorter wavelength than an oscillation wavelength of the laser chip. Photolysis and oxidation caused by the energy beam cause the removal of an adherent from the overall base or the deterioration thereof, and incidentally, the adherent is derived from an adhesive sheet used to attach the laser chip to the base, or the like. Preferably, laser light or ultraviolet light, for example, is used as the energy beam. Alternatively, the base having the laser chip mounted thereon may be irradiated with plasma so as to remove the adherent utilizing an ion cleaning effect of the plasma. After irradiation, a top is mounted to the base so as to shut off the laser chip from the outside.

Abstract: A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.