Optical control of plasmonic grating transmission by photoinduced anisotropy

Light transmission through subwavelength silver slit gratings coated with Langmuir–Blodgett films of an azo-dye compound was studied. While the coating was found to dramatically enhance the TM-polarized grating transmittance, it also enabled its low-intensity optical control: the photoinduced alignment of the azo-dye molecules yielded a significant (∼ 40 nm) shift of the extraordinary transmission peaks to shorter or longer wavelengths depending on the orientation of the induced optical axis with respect to the gratings. (paper)