According to the present invention, an integrated coupling resonator reflector (CRR) consisting of two ring resonators designed to allow optical power exchange through a directional coupler and a linear waveguide coupled thereto is integrated with a gain material. It is to realize a laser. In this configuration, if the FSR (free spectral range) of the two ring resonators combined is slightly different (i.e. slightly different circumferential length of the two resonators), and the refractive index is properly adjusted, the amount of reflectance generated in the FSR period is determined. The maximum reflectance at the wavelength that is the largest in the wavelength and separated by an integer multiple of the FSR period from the wavelength representing the maximum reflectance gradually decreases. In addition, if the refractive index difference between the two ring resonators is properly adjusted, the maximum reflectance wavelength can be changed over several tens of nm even with small refractive index changes. By using the reflection characteristics of the CRR it is possible to implement a wide-band wavelength tunable laser.; Laser Diodes, Wideband Tunable Lasers, Optical Waveguides, Reflectors, Ring Resonators, Resonators, Optical Integrated Circuits
展开▼
