| We have measured, for the first time to our knowledge, the photon statistics of parametric fluorescence from a non-degenerate optical parametric amplifier. The experimentally obtained photon-number distributions exhibit thermal-state character as predicted by the theory. However, a difference between the fluorescence gain and the signal gain of the parametric amplifier is observed. We attribute this difference to the change in the signal-beam profile during the traveling-wave pulsed amplification process.; The measurement has been performed using a novel self-homodyning technique, where the direct-detected amplified mean field serves as the local oscillator for two frequency-shifted sidebands. The obtained quadrature data are used to tomographically reconstruct the diagonal elements of the density matrix in photon-number representation. Compared to direct detection, this method offers superior quantum efficiency, speed, and mode selectivity.; We have developed techniques that allow the use of self-homodyne tomography in phase-sensitive amplifiers. We have shown, however, that the beam-profile change during amplification is detrimental to the success of self-homodyning in this configuration.; We have also used optical homodyne tomography to measure the joint statistics of twin beams emerging from the non-degenerate optical parametric amplifier. While each of the beams separately obeys thermal photon statistics, the difference between their photon numbers exhibits up to 2 dB of non-classical correlation. To our knowledge, this is the first measurement of the joint probability distribution of two quantum-correlated modes of light. |
