Surface plasmon resonance-based highly sensitive optical touch sensor with a hybrid noise rejection scheme.

摘要: A surface plasmon resonance (SPR)-based optical touch sensor structure is proposed that provides high switch sensitivity and requires a weak activating force. Our SPR-based arranged in compact Kretschmann-Raether configuration which the prism acting as our head coated with metal nanofilm. optical-based noise rejection scheme relies on wavelength filtering, spatial reflectivity of nanofilm, whereas electrical-based reduction obtained by means an electrical signal filtering process. In experimental proof concept, visible laser diode at 655 nm centered made from BK7 50 thick gold layer touching are used, showing 7.85 dB contrast ratio for first touch. An estimated mechanical force <0.1 N also observed sufficiently activates desired load. It tested 51 operations without malfunction under typical very illumination 342 3000 lx, respectively. this case, measured average 0.80 +/-0.47 fluctuation, implying refractive index change small 3.2% overall active area enough to function properly. Increasing can be accomplished using higher polarization-extinction narrower-bandwidth beam. controlled environment gold-coated thin-film sputtering technique help improve reliability durability sensor. Other key features include ease implementation, prevention light beam becoming incident user, ability accept both strong forces.