Nonclassical correlations in damped quantum solitons

Abstract

Using cumulant expansion in Gaussian approximation, the internal quantum statistics of damped soliton-like pulses in Kerr media are studied numerically, considering both narrow and finite bandwidth spectral pulse components. It is shown that the sub-Poissonian statistics can be enhanced, under certain circumstances, by absorption, which damps out some destructive interferences. Further, it is shown that both the photon-number correlation and the correlation of the photon-number variance between different pulse components can be highly nonclassical even for an absorbing fiber. Optimum frequency windows are determined in order to realize strong nonclassical behavior, which offers novel possibilities of using solitons in optical fibers as a source of nonclassically correlated light beams.

Quantum correlation and squeezing in pulses propagating in dispersion oscillating fibers

“…The formal solution of equation ( 7) is û(z, τ ) = exp(Lz)û(0, τ ). The inner product in (10) can be written as…”

“…, and H(τ ) = 0 otherwise. If the following two operators are measured by two homodyne detectors [10]:…”

“…Squeezed light is generally produced by transporting light through a nonlinear medium. Special attention was paid to the generation of squeezed states in optical solitons, using optical fibers with a Kerr nonlinearity [9][10][11]. In classical optics, fundamental solitons remain stable during propagation in optical fiber [12].…”

Mode structure and photon number correlations in squeezed quantum pulses

“…It may be very useful to separate individual nonmonochromatic modes which form the pulse. The possibility of obtaining nonclassical correlations of optical pulses by partitioning the pulse in the spectral region was suggested in [22]. Similarly as with spectral filtering, this approach is not necessarily the optimum one for obtaining maximum entanglement from the source.…”

“…One can also optimize the 2N -port parameters to prepare a set of optimally entangled K modes (multipartite entanglement), sent to different channels. This would be a generalization of the proposal of [22] for partitioning soliton pulses to generate entangled states.…”