Coherent beam combining of stimulated Brillouin scattering based multiwavelength lasers

Multiwavelength seed laser can suppress stimulated Brillouin scattering (SBS) and improve the ultimate output power of the fiber laser amplifier. Coherent combining of multiwavelength lasers/amplifiers is a promising way to get much higher total output power than coherent combining of the single frequency lasers/amplifiers. Coherent beam combining of stimulated Brillouin scattering based multiwavelength fiber lasers is proposed and demonstrated. Multiwavelength laser is generated using stimulated Brillouin scattering effect by seeded a 10 kilometer single mode fiber laser with a single frequency laser and phase locking is achieved using stochastic parallel gradient descent (SPGD) algorithm. Experiment results shows that more than 15 wavelengths are generated for the laser. With active phase control, mean power of the main-lobe in close-loop is 1.37 times of that value in open-loop and the visibility of the long exposure interference pattern is 0.37. Scale up this architecture to higher power involves introduction of power amplifiers, increasing channel number of amplifiers and power of each individual amplifier.