| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser in which narrow line width and downsizing can be achieved while ensuring long-term reliability. <P>SOLUTION: The semiconductor laser comprises a substrate, and a Fabry-Perot resonator formed on the substrate. In the Fabry-Perot resonator, a gain region, an optical waveguide coupled with the gain region, and an optical filter consisting of the drop ports of one or more ring resonators are arranged. The ring resonator is coupled with the optical waveguide through a directional coupler. Assuming the amount of detuning of the optical filter is ϕ, the line width increase factor of the gain region is α, and the coupling factor of the directional coupler is k, the following formula is satisfied. <P>COPYRIGHT: (C)2012,JPO&INPIT |
