  We study quantum correlations and quantum noise in the soliton collision
described by a general two-soliton solution of the nonlinear Schr\"odinger
equation, by using the back-propagation method. Our results include the
standard case of a $sech$-shaped initial pulse analyzed earlier. We reveal that
double-hump initial pulses can get more squeezed, and the squeezing ratio
enhancement is due to the long collision period in which the pulses are more
stationary. These results offer promising possibilities of using higher-order
solitons to generate strongly squeezed states for the quantum information
process and quantum computation.
