Coherent beam combination of narrow-linewidth 15μm fiber amplifiers in a long-pulse regime

Abstract

We report what we believe to be the first experimental demonstration of coherent beam combining of two fiber amplifiers in a 100 ns pulse regime using a signal leak between the pulses. Pulses of ∼100 W stimulated-Brillouin-scattering limited peak power are combined with 95% efficiency, a residual phase error of λ/27, and no significant beam quality degradation.

Kilowatt high average power narrow-linewidth nanosecond all-fiber laser

“…High power narrow-linewidth nanosecond lasers have attracted much attention for a range of applications such as LIDAR [1][2][3] , nonlinear frequency conversion [4][5][6] , and coherent beam combinations [7][8][9] . For nonlinear frequency conversion applications such as the optical parametric oscillator (OPO) [10,11] and second-harmonic generation (SHG) [5,6] , narrow-linewidth pulses can offer high conversion efficiency.…”

Passive coherent beam combining of two femtosecond fiber chirped-pulse amplifiers

“…This has been demonstrated in continuous-wave [3] and recently experimented in nanosecond [4] and femtosecond regimes [5][6]. This approach is scalable by increasing the number of combined amplifiers, but requires an active control of the relative phase between them.…”

Eyesafe coherent detection wind lidar based on a beam-combined pulsed laser source

“…To achieve high CBC efficiency, the phase differences are compensated using a controller. We have recently demonstrated the CBC of two amplifiers in a 100 ns pulse regime limited to 95 and 123 W, resulting in peak power of 208 W [2]. Beam quality and spectral linewidth were maintained.…”