Photon-number noise reduction from a nonlinear fiber-loop mirror

Summary form only given.Nonlinear unbalanced antiresonant ring interferometers have been proposed to provide various optical functions. The nonlinear optical-loop mirror (NOLM) is such an unbalanced fiber interferometer for ultrafast all-optical processing. Recently, it was suggested that the nonlinear input-output behavior of this device might also deamplify photon-number noise of coherent pulses below the shot-noise limit. Here, we present experimental evidence for directly detectable squeezing from a NOLM.