Results 261 to 270 of about 16,868 (292)

Quantum cascade laser spectrometers for mobile trace-gas sensing

OSA High-brightness Sources and Light-driven Interactions Congress 2020 (EUVXRAY, HILAS, MICS), 2020
Mid-IR spectroscopy using QCLs allows sensitive, selective, and fast detection of trace-gases. Recent developments permit rugged and lightweight instruments that create tantalizing options in environmental sciences and other fields, i.e. medicine or industrial process control.
Lukas Emmenegger, Manuel Graf, Philipp Scheidegger, Herbert Looser, Béla Tuzson   +4 more
openaire   +1 more source

Multi-pass quartz-enhanced photoacoustic spectroscopy-based trace gas sensing

Optics Letters, 2021
A multi-pass quartz-enhanced photoacoustic spectroscopy (MP-QEPAS)-based trace gas sensor is reported. In MP-QEPAS, a multi-pass laser beam pattern through the prong spacing of a quartz tuning fork (QTF) is obtained by means of two right-angle prisms.
Qiao, Shunda, Ma, Yufei, Patimisco, Pietro, Sampaolo, Angelo, He, Ying, Lang, Ziting, Tittel, Frank K., Spagnolo, Vincenzo   +7 more
openaire   +4 more sources

Widely Tunable Cr2+: ZnSe Laser Source for Trace-Gas Sensing

Advanced Solid-State Photonics, 2005
A continuously tunable Cr2+:ZnSe laser is applied for photoacoustic gas detection in the wavelength range of 2.0-3.1 µm. Trace-gas measurements in the 2.6-3.1 µm range with ppb sensitivity are reported for the first time.
Evgeni Sorokin, Irina T. Sorokina, Cornelia Fischer, Markus W. Sigrist   +3 more
openaire   +1 more source

Integrated Mach-Zehnder micro-interferometer for gas trace remote sensing

SPIE Proceedings, 2006
The realisation process and the preliminary tests on the performances of an integrated Mach-Zehnder Interferometer on LiNbO 3 (Lithium Niobate) substrate is presented. The microsystem has been obtained by using medium mass Ion Implantation on X-cut Lithium Niobate crystals.
Chiarini M, Bentini GG, Bianconi M, Cerutti A, Pennestrì G, Pengfei Wang, Lin She, Mazzoldi P, Sada C   +8 more
openaire   +5 more sources

Remote sensing with a triple correlation spectrometer for trace gas identification

SPIE Proceedings, 1995
We showed that the output of a cross-correlation with gas spectra could be triple-correlated to reduce the effects of Gaussian noise for improved discrimination. Such processing is directly applicable to a correlation spectrometer but could be applied to other designs.
Samuel P. Kozaitis, Bruce J. Bradshaw
openaire   +1 more source

Mitigation of atmospheric uncertainty for improved trace-gas remote sensing

Multispectral and Hyperspectral Remote Sensing Instruments and Applications II, 2005
Passive multi-spectral and hyper-spectral optical sensors offer great potential for remote-sensing in general and detection of low-concentration toxic species in particular. Correction for propagation through the intervening atmosphere (with molecular, aerosol and hydrosol constituents) is often the performance-limiting factor, a step which is ...
Joseph G. Shanks, Andrey Dudkin
openaire   +1 more source

On–off-beam quartz-enhanced photoacoustic spectroscopy trace gas sensing

Optics Letters
A novel on–off-beam quartz-enhanced photoacoustic spectroscopy (OOB-QEPAS)-based trace gas sensor was proposed for the first time (to the best of our knowledge). The on-beam and off-beam acoustic amplification modes were realized in this sensor simultaneously. The OOB configuration consists of two T-shaped resonant tubes.
Shunda Qiao, Bangyu Liu, Ziting Lang, Ying He, Haiyue Sun, Xiyang Zhi, Yufei Ma   +6 more
openaire   +2 more sources

Ultrabroadband Solid-State Lasers in Trace Gas Sensing

2008
Application of ultrabroadband Cr2+-doped mid-infrared lasers to sensitive molecular spectroscopy in the 2–3 μm wavelength range is demonstrated using two different techniques: scanning photoacoustic spectroscopy and intracavity absorption spectroscopy.
openaire   +1 more source

Fiber-ring laser-based intracavity photoacoustic spectroscopy for trace gas sensing

Optics Letters, 2017
We demonstrated a novel trace gas sensing method based on fiber-ring laser intracavity photoacoustic spectroscopy. This spectroscopic technique is a merging of photoacoustic spectroscopy (PAS) with a fiber-ring cavity for sensitive and all-fiber gas detection.
Qiang, Wang, Zhen, Wang, Jun, Chang, Wei, Ren   +3 more
openaire   +2 more sources

GASCOSCAN and GASCOFIL-Remote Sensing Gas Correlation Spectrometers for Tropospheric Trace Gas Measurements

Topical Meeting on Laser and Optical Remote Sensing: Instrumentation and Techniques, 1987
Correlation spectroscopy, which is a powerful diagnostic tool for the determination and monitoring of trace atmospheric contaminants, involves a correlative comparison between the features of a "field spectrum" of a specific region of the atmosphere, and the features of a "mask function" which is representative of the spectral absorption features of ...
W. H. Morrow, R. W. Nicholls
openaire   +1 more source