Optimum noise filtering of quantum solitons

Recently, sub-Poissonian light was generated by frequency filtering of solitons in an optical fiber. Numerical and analytical models of these experiments were developed, based on generalized P-representation and backpropagation methods. One critical issue that has not been addressed in these models is the problem of an optimum frequency- or time-filter that maximizes the observable quantum-noise reduction at the output of the optical fiber. In this regard, the solution to the matched-filter problem was derived. In addition, an analytical expression for the quantum-noise correlator of the soliton field quadrature as a function of fiber length was found, taking into account the complete contribution of the continuum.