Compact all-fiber hundred-microjoule nanosecond laser at 911 nm

In this work, we demonstrate a compact all-fiber system at 911 nm with over 100 mJ pulse energy based on homemade novel Nd-doped silica fiber, which consists of a nanosecond pulse seed and only two stage amplifiers. The seed pulse was generated by modulating a temporally stable continuous-wave Nd-doped fiber laser with an acoustic modulator.

To avoid the pulse narrowing in energy scaling process, temporal pre-shaping was also applied to the seed using a triangular wave with an inverse exponential profile. Combined with subsequent two stage amplifiers, the system achieved a laser output with a pulse energy of 148 μJ and a pulse width of 162 ns at a repetition rate of 50 kHz. The M² was measured to be 1.04.