We find that Bell’s inequality can be significantly violated (up to Tsirelson’s bound) with two-mode entangled coherent states using only homodyne measurements. This requires Kerr nonlinear interactions for local operations on the entangled coherent states. Our example is a demonstration of Bell-inequality violations using classical measurements. We conclude that entangled coherent states with coherent amplitudes as small as $0.842$ are sufficient to produce such violations.

• Received 16 February 2007

DOI:https://doi.org/10.1103/PhysRevA.75.052105