Wavelength conversion through the temporal total internal reflection in a medium with a zero-nonlinearity wavelength

We investigated the temporal total internal reflection between second-order solitons and probe pulses in a photonic crystal fiber (PCF) with a zero-nonlinearity wavelength (ZNW). Numerical simulations were performed using the photon-conserving generalized nonlinear Schrödinger equation (pcGNLSE) to eliminate nonphysical artifacts. Our results reveal that the number of wavelength conversions and their efficiency can be controlled by optimizing the initial time delay, ZNW position, and probe pulse parameters including peak power and incident wavelength. This control mechanism stems from the group velocity mismatch between the soliton and probe pulses during collisions. Notably, under the same conversion efficiency, dual-stage wavelength conversion facilitates energy transfer to a spectral region farther than that achieved via single-wavelength conversion. These findings propose a new, to our knowledge, strategy for all-optical signal processing.