Optimization and fabrication of the gold-coated GaAs diffraction gratings for surface plasmon resonance sensors

In this work we present results of theoretical and experimental investigation of the reflectance dependences in the zero diffraction order on the incident angle of the plasmon resonance sensor element on base of diffraction sinusoidal Au-coated GaAs grating. Geometrical parameters Au-coated GaAs grating to obtain high sensitive sensor element have been optimized using the rigorously coupled wave analysis simulation method. The experimental reflectance spectra of Au-coated GaAs grating created by method of interference photostimulated etching of the GaAs and deposited of the gold layer on the surface of grating by thermal spraying in a vacuum were compared with the simulated ones. Results indicate that the investigated structure can be applied to the optical refractive index sensor systems.