Investigating the Performance of Ultra-Sensitive Optical Sensor Using Plasmonic Nanoparticles

An ultra-sensitive gas nanosensor using plasmonic nanoparticles of different metallic materials such as gold, silver, copper and vanadium dioxide is introduced in this paper. The surface plasmon resonance of plasmonic material is depending on the refractive index of surrounding medium such as generic organic polymer where the refractive index is changing according to gas concentration in contact with its surface. Refractive index sensitivity and half width full maximum of the optical incident wave for different metallic nanoparticles is simulated using finite difference time domain method. Half wavelength full maximum HWFM and refractive index sensitivity are compared for different refractive indexes of single and two different sizes of different metals plasmonic nanoparticles. The effect of changing radius of the nanoparticle is also introduced for both single and two different sizes nanoparticles. Maximum refractive index sensitivity, 580 nm/RIU, is obtained using two different size gold nanoparticles by using the proposed structure.