University of Illinois Urbana-Champaign

Development of a frequency-stabalized mid-infrared external Cavity-QCL cavity ringdown spectrometer

Gibson, Bradley M.

Content Files
TJ08_Abstract.pdf
TJ08_Abstract.txt
TJ08_Presentation.pptx

Permalink

https://hdl.handle.net/2142/51154

Description

Title
Development of a frequency-stabalized mid-infrared external Cavity-QCL cavity ringdown spectrometer
Author(s)
Gibson, Bradley M.
Contributor(s)
McCall, Benjamin J.
Issue Date
2014-06-17
Keyword(s)
Instrument/Technique Demonstration
Date of Ingest
  • 2014-09-17T16:56:18Z
  • 2015-04-14T18:42:12Z
Abstract
External cavity quantum cascade lasers (EC-QCLs) provide significantly enhanced wavelength tunability while maintaining the high output powers of traditional QCLs throughout the mid-infrared portion of the spectrum. However, the inclusion of wavelength-selective moving parts allows vibrational and acoustic noise to be coupled into the laser as frequency and power noise. This can be particularly troublesome for cavity-enhanced spectroscopy, as attempts to increase vibrational isolation may interfere with stable cavity alignment. Here, we discuss our efforts to improve the frequency stability of our EC-QCL while maintaining tunability and consistent cavity alignment. A mid-infrared hollow silica waveguide is used to vibrationally isolate the laser from the cavity while maintaining alignment. To further increase frequency stability, the laser is side-of-fringe locked to an uncoated solid germanium etalon. Tunability is maintained by incrementing the angle of incidence upon the etalon using a piezo-driven mirror. Angle of incidence tuning and automated periodic re-locking are managed using a BeagleBone Black development board. This allows us to maintain essentially continuous frequency tuning between 1140-1220 \wn while stabilizing the laser's frequency to within 30 MHz. Other mid-infrared frequencies could easily be accessed by swapping QCL chips.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
English
Permalink
http://hdl.handle.net/2142/51154
DOI
https://doi.org/10.15278/isms.2014.TJ08
Copyright and License Information
Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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Abstracts & Presentations - 2014 International Symposium on Molecular Spectroscopy PRIMARY