Effect of imperfect homodyne visibility on multi-spatial-mode two-mode squeezing measurements.

摘要: We study the effect of homodyne detector visibility on measurement quadrature squeezing for a spatially multi-mode source two-mode squeezed light. Sources like optical parametric oscillators (OPO) typically produce in single spatial mode because nonlinear medium is within mode-selective cavity. For such source, imperfect interference couples additional vacuum noise, which can be accounted by introducing an equivalent loss term. In free-space multi-spatial-mode system couple uncorrelated modes, and hence cause faster degradation measured squeezing. show experimentally dependence level detectors used to probe states produced free space four-wave mixing process 85Rb vapor, also demonstrate that simple theoretical model agrees closely with experimental data.