infrared millimeter terahertz waves scientific conferences

The angular structure of an optical-terahertz biphoton field generated by strongly non-degenerate parametric down-conversion is studied theoretically. Azimuthal eigenmodes of scattered radiation are found, in the basis of which the nonlinear interaction operator has a diagonal form. The solution of the evolution equations for these eigenmodes allows us to find a scattering matrix describing the intensity and correlation properties of nonclassical optical-terahertz scattered radiation at arbitrary parametric gain and at different frequencies of the idler terahertz wave.