  The greater confinement of light that is possible in photonic crystal fibres
leads to a greater effective nonlin- earity, which promises to yield greater
quantum squeezing than is possible in standard optical fibre. However,
experimental work to date has not achieved improvements over standard fibre. We
present a comprehensive numerical investigation of polarisation squeezing in
photonic crystal fibre in a Sagnac configuration. By including loss, a
non-instantaneous Raman response, excess phase-noise, second- and third-order
dispersion and self-steepening, the simulations are able to identify the
physical factors that limit current photonic crystal fibre squeezing
experiments.
