Photon statistics of single-mode zeros and ones from an erbium-doped fiberamplifier measured by means of homodyne tomography

We report measurement of the photon-number distributions of zeros and ones that emerge from an erbium-doped fiber amplifer (EDFA) in an on-off modulat ed communication system. Single-mode single-photon resolution was achieved by employing the method of optical homodyne tomography. The measured distri butions agree with the quantum predictions of a Bose-Einstein distribution for the zeros and a Laguerre (noncentral negative binomial) distribution fo r the ones over a dynamic range up to 40 dB. The resulting noise figure of the amplifier compares well to that measured by an optical spectrum analyze r.