ENHANCED INFRARED ABSORPTION BY RHODAMINE 6G DYE ON DIFFRACTION GRATING OF THE Au/Pd THIN FILM

Today, IR nanosensors have many applications in science and technology. Extraordinary optical transmission (EOT) through an array of ordered subwave holes in a thin metallic film is used to create some kind of high-sensitivity sensor. In this work, we performed micro-hole arrays fabrication in thin film Au/Pd (80 / 20 %) by ablation technology using femtosecond laser pulses Micro-holes with diameters d ≈ 2 ÷ 3 μm and periods p ≈ 5 μm were produced. We studied the enhanced infrared absorption by Rhodamine 6G (R6G) dye on diffraction grating of the Au/Pd thin film. A deposited rhodamine layer exhibits infrared absorption, which is enhanced in the range of 1400–1600 cm –1 when approaching the edge of the first band gap with the maximum gainof about 10.