Generation of femtosecond pulse train by pulse splitting in a large mode area fiber at 2 μm wavelength

Abstract

Abstract We numerically demonstrate the generation of a very high peak power femtosecond pulse train by splitting a 1 ps, 100 kW pulse of central wavelength 2 μm using a few meters length of a large mode area fiber. The input 1 ps pulse during the propagation splits into multiple femtosecond pulses of very high peak powers. Concurrently, the spectral domain of the pulse also witnesses multiple peak formation. The used fiber is a W-type large mode area fiber, whose effective mode area can be varied from ~700 μm2 to ~1700 μm2 at 2 μm wavelength by varying the fiber parameters. The fiber design parameters were optimized for the efficient formation of femtosecond pulse train of peak powers ranging from ~100 kW to ~600 kW and FWHM ranging from ~100 fs to ~450 fs.