NDLI: Cavity enhanced absorption spectroscopy using room temperature quantum cascade lasers

Please wait, while we are loading the content...

Cavity enhanced absorption spectroscopy using room temperature quantum cascade lasers

Content Provider	Semantic Scholar
Author	Welzel, Stefan Davies, Paul B. Engeln, Rah Richard Röpcke, Jürgen
Copyright Year	2009
Abstract	Achieving the high sensitivity necessary for trace gas detection generally requires long absorption path lengths. An alternative approach to conventional linear absorption spectroscopy employing multiple pass cells is to use a high finesse cavity. With the help of such cavities the effective path length of the laser beam in the absorbing medium can essentially be increased to more than the 200 m limit usually available from conventional optical multi-pass cells while keeping the sample and pumped volume small. Optical cavity based techniques, Cavity Ring Down Spectroscopy (CRDS) and Cavity Enhanced Absorption Spectroscopy (CEAS) among them, have been successfully applied as a highly sensitive absorption technique for several years. The majority of cavity based methods have used sources of radiation in the ultraviolet and visible regions. For many years the midinfrared (MIR) molecular fingerprint region could not be employed either for CRDS or for the CEAS techniques, because of the lack of suitable radiation sources with the required power and tunability and small scale dimensions. Experiments were carried out with optical parametric oscillators, Raman cells or shifters or CO and CO2 lasers. In all these cases sophisticated optical geometries were developed which were more suitable for the research laboratory than for field applications. Attempts to use lead salt lasers clearly suffered from low laser intensity. In addition, for wider application, especially for field measurements, compact and cryogen free spectrometers are definitely preferable. Recent advances in semiconductor laser technology, in particular the advent of quantum cascade lasers (QCL) provides new possibilities for highly sensitive and selective trace gas detection using MIR absorption spectroscopy.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://meetingorganizer.copernicus.org/EGU2009/EGU2009-12890.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article

Central Library (ISO-9001:2015 Certified)
Indian Institute of Technology Kharagpur
Kharagpur, West Bengal, India | PIN - 721302

See location in the Map
03222 282435
Mail: support@ndl.gov.in

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in