Patent ID: 7873089

Claim:
A manufacture method of distributed feedback (DFB) semiconductor laser device, wherein a Bragg grating in the DFB semiconductor laser cavity is not an ordinary DFB grating but a sampled Bragg grating, in the sampled Bragg grating, there is an equivalent grating corresponding to the original ordinary DFB grating as feedback for lasing, the lasing wavelength of the DFB semiconductor laser is fallen within a forbidden band of the equivalent grating, thereby the equivalent grating is designed and fabricated by reconstruction-equivalent-chirp (REC) technology, and chirps and phase shifts in the equivalent grating are designed and fabricated using equivalent-chirp and equivalent-phase- shift methods, namely, the equivalent grating has one equivalent phase shift or multiple equivalent phase shifts and equivalent chirps, the sampled Bragg grating has multiple ghost gratings and the wavelength spacing between neighboring ghost gratings is inversely proportional to the sampling period and the effective refractive index of the semiconductor laser, only one ghost grating except the ghost grating related to the center wavelength is selected to be as equivalent grating.