FREQUENCY-CONVERSION AND AMPLIFICATION OF PHOTON-NUMBER DETECTION

We present a comparative analysis of trilinear parametric processes fo r photon-number detection. Attention is focused on those processes tha t correspond to constituent devices in optical networks, such as secon d- and subharmonic sum- and difference-frequency generation and phase- sensitive and insensitive amplification and attenuation. Gains, output Fano factors, and noise figures are given for input in both coherent and number eigenstates. The fully quantum processes (i.e., with no cla ssical pump) are evaluated numerically. It is shown that the depletion of the quantum pump is never complete and this accounts for additiona l noise at the output. Second-harmonic and sum-frequency generation tu rn out to be more efficient and less noisy than the respective down-co nversion processes. Ideal behaviors are also reported for comparison a nd the results are discussed with a brief parallel analysis of the var ious devices.