| 摘要 |
PURPOSE:To provide a semiconductor laser which oscillates at a single wavelength by adopting a distribution reflector which shows high reflectance in a wide wavelength region and a waveguide type Fabry-Pero't optical wavelength filter wherein it is used. CONSTITUTION:When current is made to flow to active waveguide regions 101, 104, laser oscillation is generated transmitting wavelength of a Fabry-pero't optical wavelength filter inside resonator is adjusted by making current flow to wavelength adjustment electrodes 9b, 9c provided to filter regions 102, 103, and oscillation wavelength is changed. Transmitting characteristic of the filter regions 102, 103 has a sharp peak periodically; however, a peak interval differs due to a difference of resonator length. In a structure wherein two filters are connected in series, only light of a wavelength lambda, wherein transmitting wevelength of both filters coincides is transmitted and the laser oscillates. Therefore, when current is made to flow through the electrode 9c on the region 103, refraction factor in the region reduces, transmitting wavelength shifts to the side of short wavelength and oscillation wavelength moves to lambda2, operational wavelength can be changed and a narrow band filter and a semiconductor laser can be acquired. |
