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 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 laser diode with which separation of a current narrowing layer is able to be prevented is provided. The laser diode includes a mesa that has a first multilayer film reflector, an active layer, and a second multilayer film reflector in this order, and has a current narrowing layer for narrowing a current injected into the active layer and a buffer layer adjacent to the current narrowing layer. The current narrowing layer is formed by oxidizing a first oxidized layer containing Al. The buffer layer is formed by oxidizing a second oxidized layer whose material and a thickness are selected so that an oxidation rate is higher than that of the first multilayer film reflector and the second multilayer film reflector and is lower than that of the first oxidized layer. A thickness of the buffer layer is 10 nm or more.

Abstract: A laser diode element assembly includes: a laser diode element; and a light reflector, in which the laser diode element includes (a) a laminate structure body configured by laminating, in order, a first compound semiconductor layer of a first conductivity type made of a GaN-based compound semiconductor, a third compound semiconductor layer made of a GaN-based compound semiconductor and including a light emission region, and a second compound semiconductor layer of a second conductivity type made of a GaN-based compound semiconductor, the second conductivity type being different from the first conductivity type, (b) a second electrode formed on the second compound semiconductor layer, and (c) a first electrode electrically connected to the first compound semiconductor layer, the laminate structure body includes a ridge stripe structure, and a minimum width Wmin and a maximum width Wmax of the ridge stripe structure satisfy 1<Wmax/Wmin<3.3 or 6?Wmax/Wmin?13.3.

Abstract: The present invention provides a semiconductor device realizing reduced occurrence of a defect such as a crack at the time of adhering elements to each other. The semiconductor device includes a first element and a second element adhered to each other. At least one of the first and second elements has a pressure relaxation layer on the side facing the other of the first and second elements, and the pressure relaxation layer includes a semiconductor part having a projection/recess part including a projection projected toward the other element, and a resin part filled in a recess in the projection/recess part.

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: A method for making a light-emitting element assembly including a support substrate having a first surface, a second surface facing the first surface, a recessed portion, and a conductive material layer formed over the first surface and the inner surface of the recessed portion, and a light-emitting element. The light-emitting element has a laminated structure including a first compound semiconductor layer, a light-emitting portion, and a second compound semiconductor layer, at least the second compound semiconductor layer and the light-emitting portion constituting a mesa structure. The light-emitting element further includes an insulating layer formed, a second electrode, and a first electrode. The mesa structure is placed in the recessed portion so that the conductive material layer and the second electrode are in at least partial contact with each other, and light emitted from the light-emitting portion is emitted from the second surface side of 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: A vertical cavity surface emitting laser includes a layer-stack structure including, on a substrate, a transverse-mode adjustment layer, a first multilayer reflecting mirror, an active layer having a light emission region, and a second multilayer reflecting mirror in order from the substrate side, and including a current confinement layer in which a current injection region is formed in a region corresponding to the light emission region in the first multilayer reflecting mirror, between the first multilayer reflecting mirror and the active layer, between the active layer and the second multilayer reflecting mirror, or in the second multilayer reflecting mirror. In the transverse-mode adjustment layer, reflectance at an oscillation wavelength in the region opposite to a center of the light emission region is higher than that at an oscillation wavelength in the region opposite to an outer edge of the light emission region.

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 element assembly includes: a laser diode element; and a light reflector, in which the laser diode element includes (a) a laminate structure body configured by laminating, in order, a first compound semiconductor layer of a first conductivity type made of a GaN-based compound semiconductor, a third compound semiconductor layer made of a GaN-based compound semiconductor and including a light emission region, and a second compound semiconductor layer of a second conductivity type made of a GaN-based compound semiconductor, the second conductivity type being different from the first conductivity type, (b) a second electrode formed on the second compound semiconductor layer, and (c) a first electrode electrically connected to the first compound semiconductor layer, the laminate structure body includes a ridge stripe structure, and a minimum width Wmin and a maximum width Wmax of the ridge stripe structure satisfy 1<Wmax/Wmin<3.3 or 6?Wmax/Wmin?13.3.

Abstract: A method for manufacturing a light emitting element including the steps of (A) sequentially forming on a substrate a first compound semiconductor layer having a first conduction type, an active layer, and a second compound semiconductor layer having a second conduction type; (B) forming a plurality of point-like hole portions in a thickness direction in at least a region of the second compound semiconductor layer located outside a region to be provided with a current confinement region; and (C) forming an insulating region by subjecting a part of the second compound semiconductor layer to an insulation treatment from side walls of the hole portions so as to produce the current confinement region surrounded by the insulating region in the second compound semiconductor layer.

Abstract: A Vertical Cavity Surface Emitting Laser capable of decreasing the lowering of the yield due to displacement and separation of a pedestal without enormous increase of the threshold value and more difficult manufacturing process is provided. A base of a mesa spreads over the top face of a lower DBR layer. The base is a non-flat face in which end faces of a plurality of layers are exposed. The non-flat face is generated due to etching unevenness in forming the mesa, and is in a state of a step in which end faces of a low-refractive index layer and a high-refractive index layer included in the lower DBR layer are alternatively exposed. At least one of the layers exposed in the non-flat face in the plurality of low-refractive index layers included in the lower DBR layer is an oxidation inhibition layer.

Abstract: A laser diode device includes a laminated structure in which a first compound semiconductor layer, a third compound semiconductor layer that has a light emitting region and a saturable absorption region, and a second compound semiconductor layer are sequentially layered, a second electrode, and a first electrode. The laminated structure has ridge stripe structure. The second electrode is separated into a first section to obtain forward bias state by applying a direct current to the first electrode through the light emitting region and a second section to add electric field to the saturable absorption region by an isolation trench. When minimum width of the ridge stripe structure is WMIN, and width of the ridge stripe structure of the second section of the second electrode in an interface between the second section of the second electrode and the isolation trench is W2, 1<W2/WMIN is satisfied.

Abstract: A method for manufacturing a light emitting element includes the steps of (A) forming sequentially a first compound semiconductor layer having a first conduction type, an active layer, and a second compound semiconductor layer having a second conduction type on a substrate, (B) forming a plurality of point-like hole portions in a thickness direction in at least a region of the second compound semiconductor layer located outside a region to be provided with a current confinement region, and (C) forming an insulating region by subjecting a part of the second compound semiconductor layer to an insulation treatment from side walls of the hole portions so as to produce the current confinement region surrounded by the insulating region in the second compound semiconductor layer.

Abstract: A laser diode assembly includes: a mode-locked laser diode device; a diffraction grating that configures an external resonator, returns primary or more order diffracted light to the mode-locked laser diode device, and outputs 0-order diffracted light outside; and an imaging section provided between the mode-locked laser diode device and the diffraction grating and imaging an image of a light output end face of the mode-locked laser diode device on the diffraction grating.

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 Vertical Cavity Surface Emitting Laser capable of decreasing the lowering of the yield due to displacement and separation of a pedestal without enormous increase of the threshold value and more difficult manufacturing process is provided. A base of a mesa spreads over the top face of a lower DBR layer. The base is a non-flat face in which end faces of a plurality of layers are exposed. The non-flat face is generated due to etching unevenness in forming the mesa, and is in a state of a step in which end faces of a low-refractive index layer and a high-refractive index layer included in the lower DBR layer are alternatively exposed. At least one of the layers exposed in the non-flat face in the plurality of low-refractive index layers included in the lower DBR layer is an oxidation inhibition layer.

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.