Fabrication of thermally stable mid-infrared optical filters using tantalum microdisc array

To fabricate a thermally stable optical filter in the mid-infrared (MIR) region, plasmonic metal disk array (PMDA) using tantalum (Ta) was proposed, and performance compared with that of conventional silver (Ag)-based PMDAs. A finite-difference time-domain method utilized to systematically analyze effects geometric configuration constituent materials on properties PMDA filters periodic hexagonal lattice. Unlike Ag filters, whose transmission dip at resonance wavelengths gradually decreased increasing temperature, Ta revealed almost same spectra even after annealing 700 °C for 30 min. The Ta-based MIR exhibited similar those PMDA. PMDAs duty cycle (d.c.) 60% stop band sufficiently deep wide linewidth. fabricated disks were demonstrated quantify different types alcohols through monitoring spectra.