Parametric amplification of random optical fields

Abstract

We demonstrate that the initiated by quantum noise parametric downconversion of pump beam can be described in classical approach as a parametric amplification of orthogonal coaxial vortex modes with random amplitudes and of various topological charges n. It is shown that in the field of Gaussian pump beam the parametric gain is largest for the fundamental mode (n = 0). The evolution of correlation in the radial spectrum of different modes under parametric amplification is analysed.
Keywords: optical parametric amplifier, optical vortex
PACS: 42.65.Yj, 42.60.Jf