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

摘要

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 mu m 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 similar to 700 mu m(2) to similar to 1700 mu m(2) at 2 mu m 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 similar to 100 kW to similar to 600 kW and FWHM ranging from similar to 100 fs to similar to 450 fs.