Photon-number squeezed solitons from an asymmetric fiber-optic Sagnac interferometer,

Direct photon-number squeezing is demonstrated, for the first time to our knowledge, in a nonlinear fiber-optic interferometer. Launching 126-fs solitons into a highly asymmetric Sagnac loop, the maximum photocurrent noise reduction was 3.9 +/- 0.2 dB below shot noise, corresponding to 6.0 +/- 0.9 dB, when corrected for linear losses. The loop is a model system for squeezing generated by the interference of two pulses after nonlinear propagation through a fiber.