Waveguide solution of the Koroteev problem in the nonlinear optics of media with broken mirror symmetry: collinear three- and five-wave mixing schemes in planar waveguides

It is shown that collinear three- and five-wave mixing schemes may operate in an isotropic gyrotropic medium (the Koroteev problem in chiral nonlinear optics) when waveguide propagation of optical waves is employed. The norma l modes (eigenmodes) of the waveguide field are characterised by the presen ce of a longitudinal electric field component, which leads to the appearanc e of a transverse nonlinear polarisation component and lifts the prohibitio n of collinear generation of the sum and difference frequencies on the basi s of a quadratic nonlinearity, and of a bioCARS signal based on a fourth-or der nonlinearity. Expressions are obtained for the amplitudes of signals ar ising as a result of such nonlinear optical mixing.