TY  - JOUR
A1  - Munzke, Dorit
A1  - Böhm, Michael
A1  - Reich, Oliver
T1  - Gaseous Oxygen Detection Using Hollow-Core Fiber-Based Linear Cavity Ring-Down Spectroscopy
JF  - Journal of lightwave technology
N2  - We demonstrate a method for the calibration-free and quantitative analysis of small volumes of gaseous samples. A 10 m hollow-core photonic bandgap fiber is used as the sample cell (volume = 0.44 mu L) and is placed inside a linear resonator setup. The application of cavity ring-down spectroscopy and in consideration of rather small coupling losses, this leads to an increased effective optical path length of up to 70 m. This implies a volume per optical interaction path length of 6.3 nL.m(-1). We used tunable diode laser spectroscopy at 760 nm and scanned the absorption for oxygen sensing. The optical loss due to sample absorption is obtained by measuring the ring-down time of light propagating inside the cavity. The resultant absorption coefficient shows a discrepancy of only 5.1% comparing to the HITRAN database. This approach is applicable for sensitive measurements if only submicroliter sample volumes are available.
KW  - Cavity ring-down spectroscopy
KW  - gas sensing
KW  - hollow-core photonic bandgap fiber
KW  - oxygen
Y1  - 2015
U6  - https://doi.org/10.1109/JLT.2015.2397177
SN  - 0733-8724
SN  - 1558-2213
VL  - 33
IS  - 12
SP  - 2524
EP  - 2529
PB  - Inst. of Electr. and Electronics Engineers
CY  - Piscataway
ER  - 
TY  - JOUR
A1  - Taubert, Andreas
A1  - Stange, Franziska
A1  - Li, Zhonghao
A1  - Junginger, Mathias
A1  - Günter, Christina
A1  - Neumann, Mike
A1  - Friedrich, Alwin
T1  - CuO nanoparticles from the Strongly Hydrated Ionic Liquid Precursor (ILP) Tetrabutylammonium Hydroxide evaluation of the Ethanol Sensing Activity
JF  - ACS applied materials & interfaces
N2  - The sensing potential of CuO nanoparticles synthesized via. precipitation from a water/ionic liquid precursor (ILP) mixture was investigated. The particles have a moderate surface area of 66 m(2)/g after synthesis, which decreases upon thermal treatment to below 5 m(2)/g. Transmission electron microscopy confirms crystal growth upon annealing, likely due to sintering effects. The as-synthesized particles can be used for ethanol sensing. The respective sensors show fast response and recovery times of below 10 s and responses greater than 2.3 at 100 ppm of ethanol at 200 degrees C, which is higher than any CuO-based ethanol sensor described so far.
KW  - ionic liquids
KW  - ionic liquid precursors
KW  - tetrabutylammonium hydroxide
KW  - nanoparticles
KW  - CuO
KW  - gas sensing
Y1  - 2012
U6  - https://doi.org/10.1021/am201427q
SN  - 1944-8244
VL  - 4
IS  - 2
SP  - 791
EP  - 795
PB  - American Chemical Society
CY  - Washington
ER  -