Results 11 to 20 of about 16,868 (292)

Chirped-pulse terahertz spectroscopy for broadband trace gas sensing

Optics Express, 2011
We report the first demonstration of a broadband trace gas sensor based on chirp-pulse terahertz spectroscopy. The advent of newly developed solid state sources and sensitive heterodyne detectors for the terahertz frequency range have made it possible to generate and detect precise arbitrary waveforms at THz frequencies with ultra-low phase noise.
Gerecht, Eyal, Douglass, Kevin O., Plusquellic, David F.   +2 more
openaire   +3 more sources

Low Power Greenhouse Gas Sensors for Unmanned Aerial Vehicles

Remote Sensing, 2012
We demonstrate compact, low power, lightweight laser-based sensors for measuring trace gas species in the atmosphere designed specifically for electronic unmanned aerial vehicle (UAV) platforms.
David J. Lary, Bryan Roscoe, William A. Harrison, Lei Tao, David J. Miller, Mark A. Zondlo, Kang Sun, David Schaefer, Amir Khan   +8 more
doaj   +2 more sources

Miniaturized Photoacoustic Trace Gas Sensing Using a Raman Fiber Amplifier [PDF]

Journal of Lightwave Technology, 2015
This paper presents the development of a Raman fiber amplifier optical source with a maximum output power of 1.1 W centered around 1651 nm, and its application in miniaturized 3D printed photoacoustic spectroscopy (PAS) trace gas sensing of methane. The Raman amplifier has been constructed using 4.5 km of dispersion shifted fiber, a 1651 nm DFB seed ...
Bauer, Ralf, Legg, Thomas, Mitchell, David, Flockhart, Gordon M. H., Stewart, George, Johnstone, Walter, Lengden, Michael   +6 more
openaire   +4 more sources

Three-dimensional radiative transfer effects on airborne and ground-based trace gas remote sensing [PDF]

Atmospheric Measurement Techniques, 2020
Air mass factors (AMFs) are used in passive trace gas remote sensing for converting slant column densities (SCDs) to vertical column densities (VCDs).
M. Schwaerzel, M. Schwaerzel, C. Emde, D. Brunner, R. Morales, T. Wagner, A. Berne, B. Buchmann, G. Kuhlmann   +8 more
doaj   +3 more sources

Tailoring MXene Thickness and Functionalization for Enhanced Room-Temperature Trace NO2 Sensing

Nano-Micro Letters
Highlights Gas-phase functionalization of X-MXene (X = –F, –OH, –O, –Br, –I) films crafted from sub-100 nm thin MXene flakes for highly sensitive NO2 sensors.
Muhammad Hilal, Woochul Yang, Yongha Hwang, Wanfeng Xie   +3 more
doaj   +2 more sources

Mixed Trace Gas Sensing for Environmental Applications

Mixed Trace Gas Sensing for Environmental Applications
Mixed gas sensing based on superluminescent diode (SLED) with Fabry-Perot etalon and vibrational coherent anti-Stokes Ramen spectroscopy (CARS) technique with single Nd^: YAG laser for mixed gases like C_2H_2 CO_2 and CH_4 /CO_2 are compared for combustion applications.
Vasa, N. J., Seeger, T., Kumaravel, M., Sulochana, K., Eichmann, S. C.   +4 more
openaire   +1 more source

Integrated Resonant Micro/Nano Gravimetric Sensors for Bio/Chemical Detection in Air and Liquid

Micromachines, 2021
Resonant micro/nanoelectromechanical systems (MEMS/NEMS) with on-chip integrated excitation and readout components, exhibit exquisite gravimetric sensitivities which have greatly advanced the bio/chemical sensor technologies in the past two decades. This
Hao Jia, Pengcheng Xu, Xinxin Li
doaj   +1 more source

Trace Gas Remote Sensing by Lasers [PDF]

Optik & Photonik, 2013
AbstractActive remote sensing represents a promising technology to accurately measure the atmospheric concentration of the climate‐relevant trace gases carbon dioxide and methane. For this application, frequency stabilized laser sources with high pulse energy emitting at specific absorption lines around 1.6 μm wavelength are required.
Oliver Lux, Haro Fritsche, Hans J. Eichler   +2 more
openaire   +1 more source

A Novel Hyperspectral Remote Sensing Technique with Hour-Hectometer Level Horizontal Distribution of Trace Gases: To Accurately Identify Emission Sources

Journal of Remote Sensing, 2023
High spatial-temporal resolution distribution of atmospheric gaseous pollutant is an important basis for tracing its emission, transport, and transformation. Typical methods for acquiring regional atmospheric gaseous pollutant distributions are satellite
Chuan Lu, Qihua Li, Chengzhi Xing, Qihou Hu, Wei Tan, Hua Lin, Jinan Lin, Zhiguo Zhang, Bowen Chang, Cheng Liu   +9 more
doaj   +1 more source

Quartz-enhanced photoacoustic-photothermal spectroscopy for trace gas sensing

Optics Express, 2021
A trace gas detection technique of quartz-enhanced photoacoustic-photothermal spectroscopy (QEPA-PTS) is demonstrated. Different from quartz-enhanced photoacoustic spectroscopy (QEPAS) or quartz-enhanced photothermal spectroscopy (QEPTS), which detected only one single kind of signal, QEPA-PTS was realized by adding the photoacoustic and photothermal ...
Yinqiu Hu, Shunda Qiao, Ying He, Ziting Lang, Yufei Ma   +4 more
openaire   +2 more sources