Strip-loaded tunable distributed feedback laser

摘要

A semiconductor laser with single longitudinal mode includes active region(s) and phase shift region(s). An optical cavity such as a passive waveguide extends through the active region(s) and the phase shift region(s). A diffraction grating in the active region(s) has a refractive index. An active layer in the active regions is located between the diffraction grating and the passive waveguide. The phase shift region(s) have a refractive index difference DELTAn with respect to the index of the active region(s). The phase shift region(s) are located adjacent to and/or between the active region(s). An optical mode is shifted in the phase shift region. An eletro-optical circuit tunes a lasing wavelength of the laser by varying DELTAn. The electro-optical circuit reverse or forward biases a tuning junction to change the refractive index difference DELTAn using field effects or carrier effects.