Abstract: A recording device that records information in an optical recording medium includes: a self excited oscillation semiconductor laser including a saturable absorber section to apply a bias voltage and a gain section to inject a gain current, and also emitting a laser light to record the information in the optical recording medium; a reference signal generation unit generating a master clock signal and also supplying an injection signal synchronized with the master clock signal to the gain section of the self excited oscillation semiconductor laser; and a recording signal generation unit generating a recording signal based upon the master clock signal and also applying the recording signal to the saturable absorber section of the self excited oscillation semiconductor laser as the bias voltage.

Abstract: Provided is a light-emitting device including (a) a layer structure obtained by sequentially growing on a base substrate a first compound semiconductor layer of a first conductivity type, (b) an active layer formed of a compound semiconductor, and (c) a second compound semiconductor layer of 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 layer structure formed of at least a part of the second compound semiconductor layer in a thickness direction of the second compound semiconductor layer. The first compound semiconductor layer has a thickness greater than 0.6 ?m. A high-refractive index layer formed of a compound semiconductor material having a refractive index higher than a refractive index of a compound semiconductor material of the first compound semiconductor layer is formed in the first compound semiconductor layer.

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 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: 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 recording device that records information in an optical recording medium includes: a self excited oscillation semiconductor laser including a saturable absorber section to apply a bias voltage and a gain section to inject a gain current, and also emitting a laser light to record the information in the optical recording medium; a reference signal generation unit generating a master clock signal and also supplying an injection signal synchronized with the master clock signal to the gain section of the self excited oscillation semiconductor laser; and a recording signal generation unit generating a recording signal based upon the master clock signal and also applying the recording signal to the saturable absorber section of the self excited oscillation semiconductor laser as the bias voltage.

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: 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: Provided is an alignment method of a semiconductor optical amplifier with which optimization of coupling efficiency between incident laser light and light waveguide of the semiconductor optical amplifier is enabled without depending on an external monitoring device. The alignment method of a semiconductor optical amplifier is a method that optically amplifies laser light from a laser light source and outputs the optically amplified laser light, which adjusts relative position of the semiconductor optical amplifier with respect to the laser light entering into the semiconductor optical amplifier by flowing a given value of current to the semiconductor optical amplifier while entering the laser light from the laser light source to the semiconductor optical amplifier so that a voltage applied to the semiconductor optical amplifier becomes the maximum.

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 light oscillation device has a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected, a light separation unit that separates a portion of laser light beams from the self oscillation semiconductor laser, a light sensing element that senses the laser light beams separated by the light separation unit, and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element.

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: There is provided a driving method of a self-oscillating semiconductor laser device including a first compound semiconductor layer having a first conductive type and composed of a GaN base compound semiconductor, a third compound semiconductor layer and a second compound semiconductor layer configuring an emission region and a saturable absorption region, are successively laminated, a second electrode formed on the second compound semiconductor layer, and a first electrode electrically connected to the first compound semiconductor layer. The second electrode is separated into a first portion to create a forward bias state by passing current to the first electrode via the emission region and a second portion to apply an electric field to the saturable absorption region by a separation groove. The current greater than a current value where kink is occurred in optical output-current characteristics is to be passed to the first portion of the second electrode.

Abstract: A method for manufacturing a light-emitting diode, which includes the steps of: providing a substrate having a plurality of protruded portions on one main surface thereof wherein the protruded portion is made of a material different in type from that of the substrate and growing a first nitride-based III-V Group compound semiconductor layer on each recess portion of the substrate through a state of making a triangle in section wherein a bottom surface of the recess portion becomes a base of the triangle; laterally growing a second nitride-based III-V Group compound semiconductor layer on the substrate from the first nitride-based III-V Group compound semiconductor layer; and successively growing, on the second nitride-based III-V Group compound semiconductor layer, a third nitride-based III-V Group compound semiconductor layer of a first conduction type, an active layer, and a fourth nitride-based III-V compound semiconductor layer of a second conduction type.

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: The present invention provides an optical device capable of suppressing a drive current and an optical output to be varied with a passage of the time. The optical device includes: an optical element including a first end face and a second end face, and emitting light having a wavelength from 300 nm to 600 nm both inclusive at least from the second end face in the first end face and the second end face; a pedestal including a supporting substrate supporting the optical element, and a connecting terminal electrically connected to the optical element; and a sealing section including a light transmitting window in each of a portion facing the first end face and a portion facing the second end face, and sealing the optical element.

Abstract: A light-emitting diode with (a) a substrate having at least one recessed portion on one main surface; (b) a sixth nitride-based III-V group compound semiconductor layer grown on the substrate without forming a space in the recessed portion; and (c) a third nitride-based III-V group compound semiconductor layer of a first conduction type, an active layer and a fourth nitride-based III-V group compound semiconductor layer of a second conduction type formed over the sixth nitride-based III-V group compound semiconductor layer, wherein, a dislocation occurring, in the sixth nitride-based III-V group compound semiconductor layer, from an interface with a bottom surface of the recessed portion in a direction vertical to the one main surface arrives at an inclined face or its vicinity of a triangle having the bottom surface of the recessed portion as a base and bends in a direction parallel to the one main surface.

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.