2-MODE HETERODYNE PHASE DETECTION

We present an experimental scheme that achieves ideal phase detection on a two-mode held. The two modes a and b are the signal and image ban d modes of a heterodyne detector, with the held approaching an eigenst ate of the photocurrent (Z) over cap=a+b(dagger). The field is obtaine d by means of a high-gain phase-insensitive amplifier followed by a hi gh-transmissivity beam splitter with a strong local oscillator at the frequency of one of the two modes.