Eye-safe single-frequency single-mode polarized all-fiber pulsed laser with peak power of 361  W

An all-fiber, single-frequency, single-mode linearly polarized, high peak power pulsed laser at 1540 nm for coherent Doppler wind lidar is demonstrated. A narrow-linewidth seed laser is pulse modulated by an acousto-optic modulator and then amplified by two-stage cascade amplifiers. An 0.8 m long erbium/ytterbium co-doped polarization-maintaining fiber with a core diameter of 10 μm is used as the gain fiber of a power amplifier, and longitudinally varied strains are applied on the gain fiber to realize approximately 3.4 times enhancement of the stimulated Brillouin scattering threshold. Peak power of 361 W pulse width of 200 ns at 10 kHz repetition rate is achieved with transform-limited linewidth and diffraction-limited beam quality. To the best of our knowledge, it is the highest peak power of an eye-safe, single-mode narrow-linewidth pulsed fiber laser based on 10 μm core diameter silica fiber.