Abstract

Quantum solitons of the nonlinear Schrodinger equation are energy eigenstates that are photonic number states for optical systems. Experiments to date have not demonstrated room-temperature photon-number squeezing beyond 10 dB. Yamamoto and coworkers¹ have reported 14-dB squeezing from a semiconductor laser cooled to 66 K, while Spalter and coworkers² have reported 4.7 dB at room- temperature using our recently reported spectrally filtered optical fiber soliton method.³ Cooling the optical fiber could increase this further, however theoretical predictions suggest a maximum of less than 8 dB even assuming ideal detectors, no additional noise sources (such as from Raman processes), and ideal, polarization-preserving, lossless fibers. One of us has proposed another approach based on the interference of solitonic fields,⁴ which we show here to be capable in the ideal case of producing pulses squeezed beyond the 10 dB limit. A practical implementation using a Sagnac optical fiber loop is described.

© 1998 Optical Society of America