Passive, Stable and Order-Adjustable SBS Q-Switching Fiber Laser

We propose a new method to separate different orders of an all-fiber passive Q-switching stimulated Brillouin scattering (SBS) laser. We use two fiber Bragg gratings connected by two circulators for the filtering. We obtain a stabilized pulse laser and measure the pulse width of different orders. The first order of SBS has a central wavelength of 1549.75 nm, an average output power of 9 mW, and a pulse width of 400 ns. The pulse width of SBS is reduced by the higher-order signals with the larger fluctuations.