Semiconductor laser device

A semiconductor laser device comprising:

• a submount;
• and
• an edge-emitting semiconductor laser chip mounted to the submount by a junction-down method,
• the semiconductor laser chip including:
• a semiconductor substrate having a first pair of a first face and a second face opposing the first face and a second pair of a first side face and a second side face opposing the first side face;
• a stacked growth layer in which m (m≥1) laser resonators are formed;
• m P electrodes connected to the m laser resonators;
• and
• an N electrode formed on a-the second face of the semiconductor substrate and having edges over a predetermined length which is shorter than the second face,
• wherein the stacked growth layer includes a first
• conductive cladding layer, a light-emitting layer having an emitter, and a second conductive cladding layer, and is formed on the first face of the semiconductor substrate, and
• when a beam emission direction of the emitter is denoted as a z-axis, a direction of the thickness of the semiconductor substrate as a y-axis, and a direction orthogonal to the z-axis and the y-axis as an x-axis, the m laser resonators are located in an area of the stacked growth layer except directly under a center of the second face of the semiconductor substrate in the x-axis direction, wherein the emitter closest to the first side face along the x-axis is located between a first virtual vertical line along the y-axis through a corresponding one of the edges of the N electrode and a second virtual line extending from an edge of the first side face of the semiconductor substrate.