Generation of ultra-compressed solitons with a high tunable wavelength shift in Raman-inactive hollow-core photonic crystal fibers

The fission of N-solitons is a key mechanism leading to the supercontinuum generation and creation of hyper-compressed pulses and solitons featuring strong wavelength tuning. Recent advances in manufacturing PCFs filled with Raman-inactive gases have motivated the authors to focus on fission driven by the third-order dispersion (TOD), and potential applications of this setting to photonics. In the absence of the Raman-induced self-frequency shift and the Raman-associated noise, fission-produced strongly compressed solitons, once generated, may propagate keeping constant internal frequencies. A higher-order N-soliton is launched into the fiber. If the TOD dispersion is very small, it can be considered as a perturbation added to the second-order dispersion. This leads to a significant increase in the largest fundamental-soliton´s peak power and compression degree, along with the increase of the wavelength shift. However, a further increase of TOD dispersion leads to a loss of the peak-power enhancement. For optimal pulse compression and wavelength conversion, a universal optimal value of TOD strength parameter was found. This optimal value is valid for any pulse duration, second- and third-order dispersion coefficients, depending solely on order N of the injected soliton. The optimal pulse-compression degree significantly exceeds previous well-known analytical predictions.