Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Wavelength modulation spectroscopy with a pulsed quantum cascade laser for the sensitive detection of acrylonitrile

Not Accessible

Your library or personal account may give you access

Abstract

A pulsed, distributed feedback (DFB) quantum cascade laser centered at 957cm1 was used in combination with a wavelength modulation spectroscopic technique for the detection of acrylonitrile. The laser was excited with short current pulses (510ns), and the pulse amplitude was modulated with a linear subthreshold current ramp at 20Hz resulting in a 2.5cm1 frequency scan. This allowed the measurement of spectroscopic features of acrylonitrile with absorption line widths of 1cm1. A demodulation approach followed by numerical filtering was utilized to improve the signal-to-noise ratio. We then superimposed a 10kHz sine wave current modulation on top of the 20Hz current ramp. The resulting high frequency temperature modulation of the DFB structure results in wavelength modulation. A minimum detectable absorbance of 105, corresponding to the sub 109 levels of acrylonitrile, was achieved with less than a minute averaging time.

© 2011 Optical Society of America

Full Article  |  PDF Article
More Like This
Off-axis cavity enhanced spectroscopy based on a pulsed quantum cascade laser for sensitive detection of ammonia and ethylene

Jagadeeshwari Manne, Alan Lim, Wolfgang Jäger, and John Tulip
Appl. Opt. 49(28) 5302-5308 (2010)

Sensitive absorption spectroscopy with a room-temperature distributed-feedback quantum-cascade laser

K. Namjou, S. Cai, E. A. Whittaker, J. Faist, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho
Opt. Lett. 23(3) 219-221 (1998)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (11)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (1)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved