Fabrication of diffraction gratings with electrically variable pitch and their effect on surface plasmon resonance

Real-time surface plasmon signal modulation was achieved by electrically varying the pitch of a nanoscale surface relief diffraction grating inscribed on an azobenzene thin film covered with a layer of silver. The azobenzene film was spin coated on an electrostrictive Lead Lanthanum Zirconate Titanate (PLZT) ceramic substrate and AC electric fields were applied longitudinally on the PLZT ceramic causing a change in the grating pitch as well as the surface plasmon resonance wavelength. This method permits extremely accurate control of the surface plasmon wavelength for tunable optics applications.