  The nonlinear propagation of light pulses in liquid-filled photonic crystal
fibers is considered. Due to the slow reorientational nonlinearity of some
molecular liquids, the nonlinear modes propagating inside such structures can
be approximated, for pulse durations much shorter than the molecular relaxation
time, by temporally highly-nonlocal solitons, analytical solutions of a linear
Schroedinger equation. The physical relevance of these novel solitary
structures, which may have a broad range of applications, is discussed and
supported by detailed numerical simulations.
