Abstract: The present invention relates to a semiconductor laser device capable of reducing a measurement error of a temperature detecting element for detecting the temperature of a semiconductor laser element and accurately controlling the temperature of the semiconductor laser element. The semiconductor laser device is used for optical analysis and includes: a semiconductor laser element; a temperature detecting element that detects the temperature of the semiconductor laser element; output terminals that output the output of the temperature detecting element to the outside; wires that electrically connect the temperature detecting element and the output terminals; and a heat capacity increasing part that is provided interposed between the temperature detecting element and output terminal, and the output terminal, and contacts with at least part of the wires to increase the heat capacity of the wires.

Abstract: The present invention enables single mode light to be stably output while also enabling the intensity thereof to be increased, and is a distributed feedback type of semiconductor laser element in which a diffraction grating is formed on a waveguide. The waveguide includes a diffraction grating portion where the diffraction grating is formed, and a flat portion having a region where the diffraction grating is not formed and whose width is broader than the diffraction grating portion. The flat portion has a connecting portion having a region whose width changes continuously approaching a connection location with the diffraction grating portion, and a high-reflection film is provided on an end surface of the flat portion that is on an opposite side from the connecting portion, while an anti-reflection film is provided on an end surface of the diffraction grating portion that is on an opposite side from the connecting portion.

Abstract: The present invention is intended to reduce variations in oscillation wavenumber of a semiconductor laser element due to the influence of circumferential temperatures. The invention includes a semiconductor laser semiconductor laser element, a temperature control part to control a temperature of the semiconductor laser element, a temperature sensor to detect a temperature of the temperature control part, and a temperature control device to control a supply signal to the temperature control part so that a detected temperature obtained from the temperature sensor reaches a predetermined target temperature. The temperature control device changes a target temperature for the temperature control part depending on a supply signal to the temperature control part.

Abstract: The present invention is intended to reduce variations in oscillation wavenumber of a semiconductor laser element due to the influence of circumferential temperatures. The invention includes a semiconductor laser semiconductor laser element, a temperature control part to control a temperature of the semiconductor laser element, a temperature sensor to detect a temperature of the temperature control part, and a temperature control device to control a supply signal to the temperature control part so that a detected temperature obtained from the temperature sensor reaches a predetermined target temperature. The temperature control device changes a target temperature for the temperature control part depending on a supply signal to the temperature control part.

Abstract: The present invention relates to a semiconductor laser device capable of reducing a measurement error of a temperature detecting element for detecting the temperature of a semiconductor laser element and accurately controlling the temperature of the semiconductor laser element. The semiconductor laser device is used for optical analysis and includes: a semiconductor laser element; a temperature detecting element that detects the temperature of the semiconductor laser element; output terminals that output the output of the temperature detecting element to the outside; wires that electrically connect the temperature detecting element and the output terminals; and a heat capacity increasing part that is provided interposed between the temperature detecting element and output terminal, and the output terminal, and contacts with at least part of the wires to increase the heat capacity of the wires.