| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a variable wavelength semiconductor laser in which limitation of the refractive index difference of an active waveguide layer and a non-active waveguide layer in the conventional structure can be avoided, degree-of-freedom in design is enhanced, and the active waveguide layer and non-active waveguide layer can have a suitable layer structure, respectively. <P>SOLUTION: In a distribution active DFB laser including a first laser part A<SB POS="POST">1</SB>and a second laser part A<SB POS="POST">2</SB>, a diffraction grating 15 is formed over the full length of an active waveguide layer 12 and a non-active waveguide layer 13. A phase shift 20 of phase shift amount Ω<SB POS="POST">BJ</SB>is inserted into the position of a diffraction grating 15 corresponding to the bonding surface of the active waveguide layer 12 and non-active waveguide layer 13, and a phase shift 21 of phase shift amount Ω<SB POS="POST">C</SB>is inserted into the position of a diffraction grating 15 corresponding to the joint of the first laser part A<SB POS="POST">1</SB>and second laser part A<SB POS="POST">2</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT |
