Light source device

A light source device comprising:

• 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;
• a planar lightwave circuit having a light incident face that faces the support face and comprising 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;
• and
• a support member bonded to the support face;
• wherein:
• the planar lightwave circuit is directly or indirectly supported by the plurality of light emitting elements, and is supported by the support member;
• the substrate comprises a first wiring layer electrically connected to the first light emitting element and the second light emitting element;
• and
• when viewed from above in a direction normal to the support face, a center of gravity of the planar lightwave circuit is positioned in a triangle formed by virtual lines connecting a center of the first light emitting element, a center of the second light emitting element, and a center of the support member.