Evolution of light trapped by a soliton in a microstructured fiber

We observe the dynamics of pulse trapping in a microstructured fiber. Few-cycle pulses create a system of two pulses: a Raman shifting soliton traps a pulse in the normal dispersion regime. When the soliton approaches a wavelength of zero group velocity dispersion the Raman shifting abruptly terminates and the trapped pulse is released. In particular, the trap is less than 4 ps long and contains a 1 ps pulse. After being released, this pulse asymmetrically expands to more than 10 ps. Additionally, there is no disturbance of the trapping dynamics at high input pulse energies as the supercontinuum develops further.