| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength-variable laser that has achieved high output while preventing its operation from being unstable.SOLUTION: A wavelength-variable laser comprises: a wavelength filter 3 including a first ring resonator 1 and a second ring resonator 2 that are formed by a waveguide including a silicon waveguide core, have resonance wavelengths of which periodically-existing intervals are different from each other, and are capable of shifting the resonance wavelength; and an integrated circuit 6 that is optically connected with the wavelength filter and sequentially including a first semiconductor optical amplifier 4 and a mirror 5 in the order from the wavelength filter side. The resonance wavelength intervals of the first ring resonator and the second ring resonator are set so that the periodically-existing resonance wavelengths of the first ring resonator and the second ring resonator accord with each other at one wavelength, and also accord with each other at a plurality of other wavelengths other than the one wavelength, and a recursive mode interval, i.e. an interval between the one wavelength and a wavelength closest to the wavelength of the plurality of other wavelengths, is wider than the reflection wavelength range of the mirror.SELECTED DRAWING: Figure 1 |
