Nonlinear optical effects of fourth order in the field in a lithium formiate crystal
Akhmanov S.A., Dubovik A.N., Saltiel S.M., Tomov I.V., Tunkin V.G.
The effective fourth-order nonlinearity was determined by measuring the relative fourth-harmonic powers generated in different directions in a lithium formiate crystal. Particular attention was paid to the influence of cascade processes on fourth-harmonic generation.