| 摘要 |
PROBLEM TO BE SOLVED: To control a horizontal mode to a fundamental horizontal mode even on high output by forming irregularities on a side end surface along the waveguide direction of a tapered part for entrapping light that enters from a beam incidence port and is waveguided. SOLUTION: When a laser beam being subjected to a fundamental single mode oscillation enters a beam incidence port 3, the beam guides a beam waveguide 6, is amplified to the laser beam with high output while a single horizontal mode is being maintained in the beam waveguide 6 being subjected to current injection and a beam amplification region 1 being widened toward the end, and is emitted from a beam emission port 4 to the outside of an element. At the element, fine irregularities 16a are formed on a side end face along the beam waveguide direction of the tapered part of a cladding layer 16, and a return beam from an element end face where the beam emission port 4 is provided reaches the side end face of the cladding layer and is scattered and lost. Also, when beams that enter the element from an area other than the beam incidence port 3 reach the recessed and projecting parts 16a, they scatter, thus preventing a fundamental horizontal mode from being disturbed and generating a diffraction limitation beam up to a high output region. |
