Abstract
It is proposed that Bessel light beams be used to pump optical parametric oscillators. The advantages of such pumping are demonstrated by a comparison with Gaussian light beams. In particular, the maximum mode coupling coefficient is achieved in a parametric oscillator pumped by a Bessel beam, which enhances parametric amplification. A nonlinear conversion regime that does not destroy the spatial structure of the intracavity fields is found. This opens up the possibility of increasing the efficiency of conversion of the energy of an input Bessel beam, compared with a Gaussian beam.