Laser light source device and laser processing apparatus

A laser light source device comprising:

• a first light emitter that emits a first laser beam;
• a second light emitter that emits a second laser beam;
• an optical element that converges the first laser beam and the second laser beam;
• a wavelength dispersing element on which the first laser beam and the second laser beam that have exited from the optical element are incident, the wavelength dispersing element causing an optical axis of the first laser beam and an optical axis of the second laser beam to coincide with one another, and then transmitting the first laser beam and the second laser beam;
• and
• a partially reflecting mirror that returns a portion of the first laser beam and a portion of the second laser beam that have exited from the wavelength dispersing element by reflection, and transmits a remaining portion of the first laser beam and a remaining portion of the second laser beam that have exited from the wavelength dispersing element, wherein
• a reflectance of the partially reflecting mirror is wavelength-dependent, and
• when optical feedback efficiency of one of the first light emitter or the second light emitter is lower than optical feedback efficiency of an other of the first light emitter or the second light emitter, a reflectance of the partially reflecting mirror for a wavelength range of the laser beam emitted from the one of the first light emitter or the second light emitter is higher than a reflectance of the partially reflecting mirror for a wavelength range of the laser beam emitted from the other of the first light emitter or the second light emitter.