Tunable narrowband plasmonic light emission from metallic crossed surface relief gratings

Plasmonic crossed surface relief gratings were fabricated using interference lithography. Their topographies were studied by AFM as a function of laser exposure time and their surface plasmon resonance at a gold-air interface was measured between crossed polarizers in transmission and in reflection modes. Both modes resulted in emitted plasmonic light at specific wavelengths related to the grating pitch, with the reflectance SPR having a much higher intensity than the transmittance SPR. The use of these gratings as plasmonic sensors was examined and their sensitivities were measured in the reflectance and transmittance modes to be 601 nm/RIU and 589 nm/RIU, respectively.