Abstract: An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration. The laser diode can be 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: 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: 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 semiconductor optical amplifier includes: a laminated structure sequentially including a first compound semiconductor layer composed of GaN compound semiconductor and having a first conductivity type, a third compound semiconductor layer having a light amplification region composed of GaN compound semiconductor, and a second compound semiconductor layer composed of GaN compound semiconductor and having a second conductivity type; a second electrode formed on the second compound semiconductor layer; and a first electrode electrically connected to the first compound semiconductor layer. The laminated structure has a ridge stripe structure. When widths of the ridge stripe structure in a light output end face and the ridge stripe structure in a light incident end face are respectively Wout, and Win, Wout>Win is satisfied. A carrier non-injection region is provided in an internal region of the laminated structure from the light output end face along an axis line of the semiconductor optical amplifier.

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 method of driving an ultrashort pulse and ultrahigh power laser diode device having a simple composition and a simple structure is provided. In the method of driving a laser diode device, light is injected from a light injection means into a laser diode device driven by a pulse current having a value 10 or more times as large as a value of a threshold current.

Abstract: A nondestructive testing method for an oxide semiconductor layer includes the steps of applying excitation light to an amorphous or polycrystalline target oxide semiconductor layer to be tested and measuring an intensity of photoluminescence in a wavelength region longer than a wavelength corresponding to a bandgap energy among light emitted from the target oxide semiconductor layer; and estimating a film property of the target oxide semiconductor layer on the basis of measurement results.

Abstract: Provided is a driving method of a mode-locked semiconductor laser device comprising a laminated structure in which a first compound semiconductor layer, a third compound semiconductor layer having an emission region and a second compound semiconductor layer are successively laminated, a second electrode, and a first electrode. The laminated structure is formed on a compound semiconductor substrate having polarity, the third compound semiconductor layer includes a quantum well structure having a well layer and a barrier layer. The well layer has a depth of 1 nm or more and 10 nm or less. The barrier layer has an impurity doping density of 2×1018 cm?3 or more and 1×1020 cm?3 or less. An optical pulse is generated in the emission region by passing a current from the second electrode to the first electrode via the laminated structure.

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.

Abstract: A method of manufacturing 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: An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration. The laser diode can be 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 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: The present invention provides a sheath for gastrostoma (1), a sheathed dilator, a gastrostomy catheter kit and a method of splitting a sheath for gastrostoma. The sheath for gastrostoma (1) includes a sheath body (11) in which a gastrostomy catheter (2) is inserted and a handle (12). The sheath for gastrostoma (1) lowers the insertion resistance of a gastrostomy catheter when inserted in a fistula before insertion of the gastrostomy catheter in the fistula for replacement in the patient's body. According to the invention, a sheath for gastrostoma, a sheathed dilator, a sheath for gastrostoma with insertion aid, a gastrostomy catheter kit and a method of splitting a sheath for gastrostoma which can lower the insertion resistance during placement of a catheter in the patient's body, facilitate air supply control of an endoscope and stabilize endoscopic visual field during surgery are provided.

Abstract: The present invention aims to provide a resin composition for toners which enables to obtain a toner having excellent low temperature fixability and high temperature offset resistance, and a toner. The resin composition for toners is obtained by reacting a mixture of a branched polyester (A) having a number average molecular weight of 2,000 to 7,000 and a hydroxyl value of 20 to 80, and a low molecular weight linear polyester (B) having a number average molecular weight of 2,000 to 5,000 and a hydroxyl number of 20 to 55, with an isocyanate compound containing two or more isocyanate groups in one molecule, which comprises a crosslinked structure of said branched polyester (A), a structure in which said branched polyester (A) and said low molecular weight linear polyester (B) are bonded by said isocyanate compound, and an unreacted portion of said low molecular weight linear polyester (B).

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 method for manufacturing a bi-section semiconductor laser device includes the steps of (A) forming a stacked structure obtained by stacking, on a substrate in sequence, a first compound semiconductor layer of a first conductivity type, a compound semiconductor layer that constitutes a light-emitting region and a saturable absorption region, and a second compound semiconductor layer of a second conductivity type; (B) forming a belt-shaped second electrode on the second compound semiconductor layer; (C) forming a ridge structure by etching at least part of the second compound semiconductor layer using the second electrode as an etching mask; and (D) forming a resist layer for forming a separating groove in the second electrode and then forming the separating groove in the second electrode by wet etching so that the separating groove separates the second electrode into a first portion and a second portion.

Abstract: A method of driving an ultrashort pulse and ultrahigh power laser diode device having a simple composition and a simple structure is provided. In the method of driving a laser diode device, light is injected from a light injection means into a laser diode device driven by a pulse current having a value 10 or more times as large as a value of a threshold current.

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.

Abstract: A nondestructive testing method for an oxide semiconductor layer includes the steps of applying excitation light to an amorphous or polycrystalline target oxide semiconductor layer to be tested and measuring an intensity of photoluminescence in a wavelength region longer than a wavelength corresponding to a bandgap energy among light emitted from the target oxide semiconductor layer; and estimating a film property of the target oxide semiconductor layer on the basis of measurement results.

Abstract: A biochemical container is provided, which can open a cover member shutting a container member and can release a tightly sealed condition, without a need for displacing the outer edge section of the cover member. In the present invention, an opening in an end of a container member 110 is openably and closably shut by a cover member 120. When an assisting-opening member 140 is pressed from the outside in such shut condition, the stress is changed to the opening direction by the changing-direction mechanism 150 to exert over the cover member 120. Consequently, the tightly sealed condition of the cover member 120 that shuts the container member 110 can be released.