Overlapped grating and chirped grating-based dual-wavelength narrow-linewidth fiber laser

The invention discloses an overlapped grating and chirped grating-based dual-wavelength narrow-linewidth fiber laser. The overlapped grating and chirped grating-based dual-wavelength narrow-linewidth fiber laser comprises a pumping source, a dual-wavelength overlapped grating, an erbium doped fiber, a chirped grating, a spectrograph and a stress adjusting device. According to the overlapped grating and chirped grating-based dual-wavelength narrow-linewidth fiber laser of the invention, the overlapped grating and the chirped grating are adopted as wavelength selection devices, and therefore, structural simplicity and dual-wavelength laser output can be realized; and the spectrum analyzer is adopted to perform measurement, and the minimum wavelength resolution of an output spectrum is 0.01nm; the overlapped grating and the chirped grating form a resonant cavity, and therefore, connection loss is small, and parameter adjustment is flexible; and the whole device is compact and reliable, and has great application potential in the aspect of optical fiber system integration.