LASER OSCILLATOR

A laser oscillator of the present invention comprises: a semiconductor laser module; a first optical fiber for propagating a laser beam from the semiconductor laser module; and a first prism including a first input surface fusion-bonded to the first optical fiber and receiving the laser beam having been input from the first optical fiber, a first reflection surface for reflecting the laser beam having been input from the first input surface and for transmitting a stimulated Raman scattered beam, and a first output surface for outputting the laser beam having been reflected on the first reflection surface.