title: Holographic chemical vapor sensor.
abstract: A holographic interferometer senses vapor-induced optical path length changes in polymer or other chemically sensitive films. The interferometer is inherently sensitive to changes in chemical vapor content, self-compensates for drifts, and accommodates a large array of sensor elements. A sniff-locked-loop synchronous detection method takes advantage of the interferometer's rapid response to achieve vapor concentration sensitivity in the parts-per-billion (ppb, parts in 10(9)) range. We demonstrate, for example, 40 ppb sensitivity to ethyl alcohol using poly(N-vinyl pyrrolidone) with a measurement time of 5 s.
authors: Department of Physics and JILA, National Institute for Standards and Technology, JILA UCB 440, University of Colorado at Boulder, Boulder, Colorado 80309-0440, USA.
authors: Hongke
authors: H
authors: Ye
authors: Oyvind
authors: O
authors: Nilsen
authors: Victor M
authors: VM
authors: Bright
authors: Dana Z
authors: DZ
authors: Anderson
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis*; D005740:Gases / Q000032:analysis*; D006696:Holography / Q000295:instrumentation* / Q000379:methods; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D014159:Transducers
chemical_list: D005740:Gases; D000431:Ethanol