Envelope time reversal with a nonlinear time lens based on accelerating quasi-phase-matching

We show theoretically and numerically that a time-reversed replica of the pump pulse envelope in a frequency converted signal can be achieved using a nonlinear time lens realized with an accelerating spatiotemporal quasi-phase-matching (QPM) modulation. The nonlinear process depends on a suitable combination of the input and output dispersion and acceleration rate of a quadratic spatiotemporal QPM modulation.