Quasi-phase Matched Four-wave Mixing in Gas-filled Multipass Cell: An Experimental Study

MultiPass Cells (MPC) are intensively used recently in the femtosecond community because they enable compression of picosecond and multi hundreds of femtosecond lasers down to sub-100 fs pulse duration with a transmission above 90% [1]. In this contribution, we observe and study a quasi-phase matched four-wave mixing (FWM) process inside a gas-filled MPC. This phenomenon was first observed at the output of highly nonlinear MPCs [2], and a theoretical explanation was later proposed [3]. Here, by experimentally observing the development of the parametric generation process along propagation, we confirm its physical origin, and study how it evolves as a function of various parameters.