MODELING OF LARGE-BANDWIDTH PARAMETRIC AMPLIFICATION IN THE CERENKOV-IDLER CONFIGURATION IN PLANAR WAVE-GUIDES

Parametric amplification in the Cerenkov-idler configuration, in which the pump and the signal fields form guided waves of a planar waveguid e while the idler is radiated into the substrate, is analyzed by a cou pled-mode approach. Using the quasi-phase-matching scheme for periodic ally domain-reversed proton-exchanged LiNbO3 waveguides upon a Z-cut s ubstrate, we have shown that this novel configuration has a large sign al gain bandwidth and is more tolerant of variations in pump frequency than the all-guided configuration is. One can compensate for the rela tively lower gain in the proposed configuration by increasing the inte raction length. For typical values of various parameters, numerical re sults for optimum waveguide parameters (corresponding to maximum signa l gain) for a given pump and signal wavelength are presented. Similarl y, for a given waveguide the optimum combination of the pump and the s ignal wavelengths has been estimated. This configuration is expected t o find applications in the realization of practical parametric amplifi ers and oscillators. (C) 1997 Optical Society of America.