Laser device, laser machining device and optical amplifier

摘要

A laser device that includes a laser beam guide portion (1) and an excitation beam guide portion (2) for confining an excitation beam and introducing the excitation beam into the laser beam guide portion (1) in a distribution state to perform laser oscillation or amplification. The excitation beam guide portion (2) is formed by winding or rounding a flexible beam guide member (21) having a ribbon-like or a sheet-like shape to form a thin integral body as a beam guide structure.