hide
Free keywords:
-
Abstract:
Generation of a fifth harmonic by the cascading of two phase-matched third-order processes in a single centrosymmetric nonlinear medium with a focused fundamental beam is investigated theoretically. With the help of analytical and numerical investigations the optimized conditions for maximum conversion into the fifth harmonic are found. In general the optimal position of focusing depends on the values of the mismatches Δk1 and Δk2 for both "steps" of the third order cascading (ω+ω+ω=3ω; 3ω+ω+ω=5ω). It is shown that for best efficiency this method of fifth harmonic generation requires specially chosen Δk1,opt and Δk2,opt and focusing in the center of the nonlinear media. If the phase matching parameters are fixed and they deviate from the optimal values, then the optimal strength of focusing and position of the focus spot should be calculated according to the analysis presented here.
