Abstract: A ridge type semiconductor optical device includes a first conductivity type semiconductor layer including at least a first stripe section; an active layer including at least an active stripe section on the first stripe section; a second conductivity type semiconductor layer including at least a second stripe section on the active stripe section; a ridge electrode on the second stripe section; an insulation film on an end face of each of the first stripe section, the active stripe section, and the second stripe section; and a film heater on the insulation film, the film heater overlapping with the end face of at least the first stripe section.

Abstract: A semiconductor optical device includes an element structure layer that includes a mesa stripe extending in a first direction; an electrode film that covers at least an upper surface of the mesa stripe; an electrode pad portion that covers a part of a first region positioned in a second direction, intersecting the first direction, relative to the mesa stripe on an upper surface of the element structure layer and is electrically connected to the electrode film; a first dummy electrode that covers another part of the first region and is electrically insulated from the electrode film; and a second dummy electrode that covers at least a part of a second region positioned in a third direction, opposite to the second direction, relative to the mesa stripe on the upper surface of the element structure layer and is electrically insulated from the electrode film, wherein the first dummy electrode includes a first portion disposed in the first direction relative to the electrode pad portion and a second portion dispose

Abstract: A modulation doped semiconductor laser includes a multiple quantum well composed of a plurality of layers including a plurality of first layers and a plurality of second layers stacked alternately and including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the plurality of first layers including the acceptor so that a p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the acceptor so that the p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the donor, and an effective carrier concentration corresponding to a difference between the p-type carrier concentration and an n-type carrier concentration is 10% or less of the p-type carrier concentration of the plurality of second l

Abstract: A ridge type semiconductor optical device includes a first conductivity type semiconductor layer including at least a first stripe section; an active layer including at least an active stripe section on the first stripe section; a second conductivity type semiconductor layer including at least a second stripe section on the active stripe section; a ridge electrode on the second stripe section; an insulation film on an end face of each of the first stripe section, the active stripe section, and the second stripe section; and a film heater on the insulation film, the film heater overlapping with the end face of at least the first stripe section.

Abstract: An optical subassembly may include a plurality of optical semiconductor devices arrayed such that a plurality of light beams respectively traveling in parallel in a first direction are emitted therefrom or incident thereon. The optical subassembly may also include a carrier on which the plurality of optical semiconductor devices are mounted. Adjacent ones of the plurality of optical semiconductor devices may be located at positions shifted in a second direction orthogonal to the first direction and may be shifted in the first direction so as not to face each other in the second direction.

Abstract: A modulation doped semiconductor laser includes a multiple quantum well composed of a plurality of layers including a plurality of first layers and a plurality of second layers stacked alternately and including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the plurality of first layers including the acceptor so that a p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the acceptor so that the p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the donor, and an effective carrier concentration corresponding to a difference between the p-type carrier concentration and an n-type carrier concentration is 10% or less of the p-type carrier concentration of the plurality of second l

Abstract: An optical subassembly may include a plurality of optical semiconductor devices arrayed such that a plurality of light beams respectively traveling in parallel in a first direction are emitted therefrom or incident thereon. The optical subassembly may also include a carrier on which the plurality of optical semiconductor devices are mounted. Adjacent ones of the plurality of optical semiconductor devices may be located at positions shifted in a second direction orthogonal to the first direction and may be shifted in the first direction so as not to face each other in the second direction.

Abstract: A semiconductor optical device includes an element structure layer that includes a mesa stripe extending in a first direction; an electrode film that covers at least an upper surface of the mesa stripe; an electrode pad portion that covers a part of a first region positioned in a second direction, intersecting the first direction, relative to the mesa stripe on an upper surface of the element structure layer and is electrically connected to the electrode film; a first dummy electrode that covers another part of the first region and is electrically insulated from the electrode film; and a second dummy electrode that covers at least a part of a second region positioned in a third direction, opposite to the second direction, relative to the mesa stripe on the upper surface of the element structure layer and is electrically insulated from the electrode film, wherein the first dummy electrode includes a first portion disposed in the first direction relative to the electrode pad portion and a second portion dispose

Abstract: A chain abnormality detection device provided at a predetermined location on a circulation path of an endless chain includes a measurement start position detector, a reference position detector, and a distance measurement unit. The measurement start position detector detects that a measurement start position comes to a first predetermined position, and the reference position detector detects a timing when a reference position comes to a second predetermined position. The distance measurement unit measures a distance from the reference position to a subsequent reference position, at each of the timings. A difference calculator is provided which calculates a difference between the distance measured at the present time and the distance measured at the previous time, for the same reference position, and a breakage determination unit is provided which determines whether there is partial breakage, on the basis of the difference calculated by the difference calculator.

Abstract: A vertical circulating conveyor includes a lowering path part (3) and a raising path part (4) that connect end portions of a conveyance path part (1) and a return path part (2) vertically positioned in a linear arrangement. The lowering path part (3) includes front wheel lowering guide rails (8A) to guide front wheels (F) of a transport vehicle (5) and rear wheel lowering guide rails (8B) to guide rear wheels (R) of the transport vehicle (5). The transport vehicle (5) is moved in the lowering path part (3) by falling under its own weight in almost the horizontal state in a powerless manner while the front wheels (F) of the transport vehicle (5) are guided by the front wheel lowering guide rails (8A) and the rear wheels (R) of the transport vehicle (5) are guided by the rear wheel lowering guide rails (8B).

Abstract: An optical module is attachable to and detachable from a cage. The optical module includes a module case, a slider attached to the outside of the module case for releasing coming-off prevention from the cage, and a leakage reducing layer intervening between the module case and the slider to reduce leakage of an electromagnetic wave.

Abstract: A vertical circulating conveyor includes a lowering path part (3) and a raising path part (4) that connect end portions of a conveyance path part (1) and a return path part (2) vertically positioned in a linear arrangement. The lowering path part (3) includes front wheel lowering guide rails (8A) to guide front wheels (F) of a transport vehicle (5) and rear wheel lowering guide rails (8B) to guide rear wheels (R) of the transport vehicle (5). The transport vehicle (5) is moved in the lowering path part (3) by falling under its own weight in almost the horizontal state in a powerless manner while the front wheels (F) of the transport vehicle (5) are guided by the front wheel lowering guide rails (8A) and the rear wheels (R) of the transport vehicle (5) are guided by the rear wheel lowering guide rails (8B).