Patent ID: 7245804

Claim:
A laser device comprising: laser elements; optical fibers each including cladding surrounding a core, and including an incidence end and an emission end portion; and a laser emission portion at which emission end portions of a plurality of the optical fibers are arranged in the form of a bundle and integrated for emitting a single emission beam, the laser emission portion being provided with a plurality of laser modules that include condensing optical systems which focus laser beams emitted from the laser elements and cause the laser beams to enter through incidence ends of the optical fibers, wherein a thickness h of the cladding of each of the plurality of optical fibers is set to a value calculated in accordance with the following equation: cladding thickness ⁢ ⁢ h ≤ ( emission ⁢ ⁢ light ⁢ ⁢ amount of ⁢ ⁢ one ⁢ ⁢ laser ⁢ ⁢ module ⁢ ⁢ W required intensity ⁢ ⁢ C × packing ratio ⁢ ⁢ P - core diameter ⁢ ⁢ t ) ÷ 2.