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Published on: August 5, 2013
Cavity-ringdown molecular spectroscopy based on an optical frequency comb at 1.45-1.65 microm
Michael J Thorpe1, Darren D Hudson, Kevin D Moll
1JILA, National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA.
Optics Letters
|January 12, 2007
Summary
This study presents an improved, cost-effective optical frequency comb spectrometer for high-sensitivity molecular absorption detection. The system achieves excellent sensitivity for analyzing various gas spectra, including CO, NH3, and C2H2.
Area of Science:
- Spectroscopy
- Laser Technology
- Analytical Chemistry
Background:
- Optical frequency comb-based cavity-ringdown spectroscopy offers high sensitivity for molecular detection.
- Existing systems can be complex and expensive.
Purpose of the Study:
- To demonstrate an improved, inexpensive, simple, and robust spectrometer for molecular absorption detection.
- To achieve high sensitivity over a broad spectral range using a specific laser source.
Main Methods:
- Utilized a mode-locked erbium-doped fiber laser source centered at 1.5 micrometers.
- Developed a cavity-ringdown spectroscopy system with a large spectral bandwidth (1.45-1.65 micrometers).
Main Results:
- Achieved high sensitivity for molecular detection, approaching 1 part in 10^9 volume level.
- Measured rovibrational spectra for CO, NH3, and C2H2.
- Demonstrated an absorption sensitivity of 2 x 10^-8 cm^-1 Hz^-1/2 per detection channel.
Conclusions:
- The developed spectrometer is a cost-effective and robust tool for sensitive molecular analysis.
- The system's broad bandwidth and high sensitivity enable the study of diverse molecular absorptions.
- This technology has potential applications in environmental monitoring and chemical analysis.
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