Metamaterial enhanced ultrasensitive spectroscopy techniques

Experimental and theoretical studies of a metamaterial enhanced vibrational spectroscopy techniques are presented. We design a metamaterial consisting of vertically oriented metal insulator metal (MIM) structures with a 25 nm gap sandwiched between two metal films. By using vertical-oriented MIM structure we successfully detected 20 ppm concentration of carbon dioxide and butane molecules with negligible background noise. Metasmaterial structure was also applied for the vibrational CD spectroscopy by exploiting super-chiral field. We experimentally demonstrate high-sensitive mirror symmetric vibrational CD spectra of D- and L-alanine depending on the handedness of the metamaterial structures.