Supercontinuum Generation in a Nitrogen filled Multipass Cell

Efficient supercontinuum generation and Raman red shifting for sub-300 fs pulses was recently demonstrated in hollow core fibers [1] , [2] . Theses sources serve as a highly promising alternative to optical parametric amplifiers and as wavelength tunable sources for further frequency conversion into deep UV or THz ranges. Yetterbium based systems, due to their high average power are of key interest to drive the supercontinuum generation. Alternative approach relying on gas filled multi-pass cells (MPC) showed strong spectral broadening via self-phase modulation in a single or cascaded stages [3] . The technique uses a pair of concave mirrors arranged in a resonator like geometry with a nonlinear medium in between, either bulk or gas. It proved large compression ratios as well as high peak and average power scalability reaching down to sub-20 fs durations [4] and 1 kW average power [5] . In this work, for the first time, we demonstrate experimentally that super continuum generation strongly enhanced by rotational nonlinearities can be efficiently driven in a single MPC. This kind of systems hold promise to serve as a next-generation power-scalable, simple and stable approach of wavelength tuning and supercontinuum generation for a plethora of applications.