| 摘要 |
PURPOSE:To obtain laser beams having excellent single mode properties by forming structure, in which end face reflectivity on a laser-beam outgoing end face in a waveguide layer is brought to 1% or less, into a laser element. CONSTITUTION:Laser beams 21 generated reach the end face 9a of an SiN film 9, but power reflectivity R on the end face 9a is brought to 0. 5% or less when the thickness of the SiN film 9 extends over 2100 + or -20Angstrom , and laser beams reflected to the region 6a side of an external waveguide layer 6 is reduced extremely. Consequently, laser beams 21 generated from an active waveguide layer region 20 in the external waveguide layer 6 are almost not subject to the effect of the reflected laser beams of previously generated laser beams, and laser beams 21 transmit the SiN film 9 and are radiated outside a laser element. Accordingly, laser beams 21 radiated outside the laser element are formed in laser beams having excellent single mode properties. |
