Nonlinear modulated ellipsometry for characterization of biopolymers

Sensitive and easy in operation met hod based on nonlinear polarizat ion transformation at two-beam paramet ric interact ion in macroscopically isot ropic media is analyzed theoretically and demonst rated experimentally for characterizat ion of response and relaxation of the third-order nonlinearity in biopolymer materials like bacteriorhodopsin. The method is shown to be an effective tool for obtaining rat her complete information about nonlinear parameters of biopolymers: mnit ude and sign of real and imaginary parts of nonlinearity tensor components, time of nonlinearity relaxation and others.