Miniature Chemical Sensor Combining Molecular Recognition with Evanescent Wave Cavity Ring-Down Spectroscopy

Pipino, Andrew C. R. ; Meuse, Curt W.

National Institute of Standards and Technology, Gaithersburg, MD (United States)

关键词: Management;    Reflection;    Resonators;    Absorption;    37 Inorganic, Organic, Physical And Analytical Chemistry;   

DOI  :  10.2172/839390
RP-ID  :  EMSP-73844
RP-ID  :  AI07-97ER62518
RP-ID  :  839390

美国|英语

来源: UNT Digital Library

【 摘 要 】

A new chemical detection technology has been realized through EMSP Projects 60231 and 73844 that addresses DOE environmental management needs. The new technology is based on a variant of the sensitive optical absorption technique, cavity ringdown spectroscopy (CRDS). Termed evanescent-wave cavity ring-down spectroscopy (EW-CRDS), the technology employs a miniature solid-state optical resonator having an extremely high Q-factor as the sensing element, where the high-Q is achieved by using ultra-low-attenuation optical materials, ultra-smooth surfaces, and ultra-high reflectivity coatings, as well as low-diffraction-loss designs. At least one total-internal reflection (TIR) mirror is integral to the resonator permitting the concomitant evanescent wave to probe the ambient environment. Several prototypes have been designed, fabricated, characterized, and applied to chemical detection. Moreover, extensions of the sensing concept have been explored to enhance selectivity, sensitivity, and range of application. Operating primarily in the visible and near IR regions, the technology inherently enables remote detection by optical fiber. Producing 11 archival publications, 4 conference proceedings, 5 patents, 19 invited talks, a CRADA, and a patent-license agreement, Projects 60231 and 73844 realized a new chemical detection technology providing >100 times more sensitivity than comparable technologies, while also providing practical advantages.