High peak power sub-nanosecond 2.1 μm Raman generator

Lasers operating in the 2.1 μm band are important beam sources with a wide range of applications. However, previous investigations have primarily focused on quasi-continuous-wave and Q-switched regimes with nanosecond pulse durations. In this work, a 1064 nm laser with a pulse-width of 491 ps was used to pump high-pressure nitrogen, and a 2111 nm Raman laser (second Stokes, S2) was generated. Through systematic optimization of the experimental parameters, a maximum output energy of 67.9 mJ at 2111 nm was achieved, the pulse-width was estimated to be narrower than 387 ps, and peak power was expected to be more than 175.5 MW, and the beam quality was measured to be Mx2=2.82, My2=2.96. This work presented a novel, to the best of our knowledge, approach for generating high peak power sub-nanosecond 2.1 μm lasers with good beam quality.