Amplitude-squeezed solitons from an asymmetric fiber interferometer.

We experimentally demonstrate a new scheme for generating amplitude-squeezed solitons in an asymmetric fiber Sagnac loop. We measure by direct detection what is to our knowledge a record reduction of 5.7+/-0.1 dB (73%) and, with corrections for linear losses, 6.2+/-0.1 dB (76%) in the photon-number fluctuations below the shot-noise level. The same scheme is also shown to generate significant classical noise reduction and is limited by Raman effects in fiber.