Near-degenerate cascaded four-wave mixing in an optical parametric amplifier

Efficient generation of new spectral components owing to second-order cascading in a seeded broadband beta -barium borate typeI phase-matching parametric amplifier is demonstrated. One can vary the number and magnitude of these components by changing amplification bandwidth (wavelength) and phase-matching conditions. The phenomenon is treated theoretically by use of a formalism developed previously for the case of cascaded self-diffraction.