Nonlinear optical method for the investigation of spectral properties of biomolecular complexes: second harmonic generation in ordered structures of bacteriorhodopsin

摘要

For the first time the method of the second harmonic generation was used to study the photo- and electrically induced nonlinear optical transformations in thin oriented films of purple membranes (PM). Variations of the film nonlinear susceptibility were investigated as the bacteriorhodopsin (bR) molecule underwent the cycle of photoinduced transformations for both dry electrically oriented films and bR molecules embedded into poly(vinyl alcohol) matrix. The electrically induced changes of the nonlinear optical properties were studied for the electrostatic field strength up to the values 4 $DOT 10$+4$/ V/cm. Nonlinear susceptibilities of oriented and nonoriented dried PM films are compared.