Characterization of Electrostriction Nonlinearity in a Standard Single-Mode Fiber Based on Coherent Detection and Cross-Phase Modulation

The electrostriction nonlinearity in a standard single mode fiber is measured by cross-phase modulation (XPM) between pump and probe. Novel use of a coherent homodyne receiver allows measurement of in-phase and quadrature components of the probe field, eliminating the need for an optical interferometer. The Kerr effect (γ_k) and frequency-dependent electrostriction (γ_e) nonlinear parameters are characterized experimentally, and γ_e is found to be approximately one third of γ_k at the highest peak resonance frequency. The joint action of γ_k and γ_e also introduces a polarization dependence of the electrostrictive signal when the pump and the probe are not copolarized.