Architecture for high-conversion-efficiency optical parametric oscillators

We report on the theoretical analysis of an optical parametric oscillator i n which a succession of parametric amplifications takes place to achieve mo re than 200% quantum efficiency at the wavelength of interest. The first in teraction generates the desired radiation, which we call the signal, whatev er its wavelength, and its complement, which we called the idler. When the idler is of no particular interest it is used as the pump in a second inter action to amplify the same signal, increasing the quantum efficiency for th is radiation. The same type of process can be applied again until the maxim um efficiency is reached. (C) 1999 Optical Society of America [S0740-3224(9 9)02410-8].