Nonlinear absorption property and its photonics applications of bacteriorhodopsin film

The nonlinear absorption property of bacteriorhodopsin film illuminated by two beams with different wavelength was theoretically studied. When these two beams are illuminated on the film, the optical intensity of either beam is affected by the film parameters and the optical intensity of another beam, so that one beam can be used as signal light while another beam can be used as modulation light. Thus the film can be used to realize optical numerical subtraction and is applied to make spatial light modulator for nonlinear-optical filtering.