Semiconductor laser machine

A semiconductor laser machine comprising:

• a semiconductor laser element including a first end face adapted to emit a laser beam and a second end face that is opposite the first end face;
• a heat sink;
• and
• a sub-mount adapted to fix the semiconductor laser element to the heat sink, wherein
• the sub-mount includes:
• a substrate adapted to relieve thermal stress;
• a solder layer joined to the semiconductor laser element;
• and
• a junction layer formed between the substrate and the solder layer,
• compared with the semiconductor laser element, the substrate is extended in a rearward direction that is from the first end face toward the second end face, and
• the solder layer and the junction layer are removed behind the second end face, wherein
• the solder layer and the junction layer have respective rear edges positioned forwardly of the second end face, and
• a front edge of the solder layer and a front edge of the junction layer are aligned with a front end face of the substrate.