Study of wavelength-dependent pulse self-compression for high intensity pulse propagation in gas-filled capillaries

We theoretically investigate the wavelength-dependent pulse self-compression dynamics of intense femtosecond laser pulses in gas-filled capillaries. Simulations with λ = 1, 2, 3 and 4 µm using the multimode carrier-resolved unidirectional pulse propagation equation reveal pulse self-compression or pulse broadening depending on plasma and modal dispersion. Our study shows that the pulse at 1 µm exhibits better pulse self-compression compared with longer wavelengths due to smaller group velocity mismatch between fundamental and higher-order capillary modes.