A three-color light source 1 is a three-color light source that combines red, green, and blue laser light so as to output light. The three-color light source 1 includes a red LD 11, a green LD 12, a blue LD 13, a first collimator lens 61, a second collimator lens 62, a third collimator lens 63, a first wavelength filter 81, a second wavelength filter 82, a carrier 30 that is equipped with the LDs 11 to 13, the collimator lenses 61 to 63, and the wavelength filters 81 and 82, and a TEC 40 that is equipped with the carrier 30. The red LD 11 is formed of a GaAs-based material, and the green LD 12 and the blue LD 13 are formed of GaN-based materials.

A three-color light source 1 is a three-color light source that combines red, green, and blue laser light so as to output light. The three-color light source 1 includes a red LD 11, a green LD 12, a blue LD 13, a first collimator lens 61, a second collimator lens 62, a third collimator lens 63, a first wavelength filter 81, a second wavelength filter 82, a carrier 30 that is equipped with the LDs 11 to 13, the collimator lenses 61 to 63, and the wavelength filters 81 and 82, and a TEC 40 that is equipped with the carrier 30. The red LD 11 is formed of a GaAs-based material, and the green LD 12 and the blue LD 13 are formed of GaN-based materials.

A three-color light source 1 is a three-color light source that combines red, green, and blue laser light so as to output light. The three-color light source 1 includes a red LD 11, a green LD 12, a blue LD 13, a first collimator lens 61, a second collimator lens 62, a third collimator lens 63, a first wavelength filter 81, a second wavelength filter 82, a carrier 30 that is equipped with the LDs 11 to 13, the collimator lenses 61 to 63, and the wavelength filters 81 and 82, and a TEC 40 that is equipped with the carrier 30. The red LD 11 is formed of a GaAs-based material, and the green LD 12 and the blue LD 13 are formed of GaN-based materials.

A semiconductor laser element includes an inclined substrate, a semiconductor layer formed on one surface of the substrate, a first electrode (n-type electrode) formed on an opposite surface of the substrate, a second electrode (p-type electrode) formed on the semiconductor layer, and a current constriction part formed in the semiconductor layer. The semiconductor layer has a multi-layer structure including at least an active layer. The current constriction part causes a current to concentrate and flow to a particular area of the active layer. The first electrode or the second electrode is joined to a sub-mount. In one embodiment, the location of the current constriction part in a chip width direction is between the center of one of the first and second electrodes, which is joined to the sub-mount, and the center of the other electrode, which is not joined to the sub-mount, when viewed in the chip width direction.

A semiconductor laser element includes an inclined substrate, a semiconductor layer formed on one surface of the substrate, a first electrode (n-type electrode) formed on an opposite surface of the substrate, a second electrode (p-type electrode) formed on the semiconductor layer, and a current constriction part formed in the semiconductor layer. The semiconductor layer has a multi-layer structure including at least an active layer. The current constriction part causes a current to concentrate and flow to a particular area of the active layer. The first electrode or the second electrode is joined to a sub-mount. In one embodiment, the location of the current constriction part in a chip width direction is between the center of one of the first and second electrodes, which is joined to the sub-mount, and the center of the other electrode, which is not joined to the sub-mount, when viewed in the chip width direction.

A light source device includes: a substrate having a support face; a plurality of light emitting elements disposed on the support face, the plurality of light emitting elements including a first light emitting element and a second light emitting element, each of which is a vertical-cavity surface-emitting laser element; and a planar lightwave circuit having a light incident face that faces the support face and including a plurality of optical waveguides configured to guide light that has exited from the respective plurality of light emitting elements and entered the light incident face. The planar lightwave circuit is directly or indirectly supported by the plurality of light emitting elements. The substrate includes a first wiring layer electrically connected to the first light emitting element and the second light emitting element.