LASER OSCILLATOR, LASER MACHINING DEVICE, OPTICAL FIBER, OPTICAL FIBER PRODUCTION METHOD, AND, OPTICAL FIBER PRODUCTION DEVICE

摘要

The present invention achieves strong laser oscillation in a laser oscillator which uses an optical fiber. A laser oscillator 1 comprises an excitation light source 11, an optical fiber 15, and a grating region 155. The excitation light source 11 outputs excitation light L2. The optical fiber 15 has a core 151 which propagates, along the length direction thereof, laser light L1 generated by the excitation light L2, and outputs the same from an outlet O. In the grating region 155, a plurality of refractive index modulation regions HR are formed at a first interval D1 in the length direction of the core 151. The refractive index modulation regions HR have a different refractive index than the refractive index of the core 151. The cross sectional area of the refractive index modulation regions HR in a direction perpendicular to the length direction of the core 151 is at least 16% of the cross sectional area of the core 151 in the direction perpendicular to the length direction.