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Updated: Jul 6, 2026
08:22
Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
On-line multicomponent trace-gas analysis with a broadly tunable pulsed difference-frequency laser spectrometer.
1Institute of Quantum Electronics, Swiss Federal Institute of Technology, ETH, CH-8093 Zurich, Switzerland.
Applied Optics
|March 8, 2008
Summary
A new automated laser spectrometer offers sensitive, real-time trace gas detection. This compact instrument achieves parts-per-billion sensitivity for methane and other gases, enabling broad environmental monitoring applications.
Area of Science:
- Spectroscopy
- Laser Technology
- Environmental Science
Background:
- Accurate and sensitive detection of trace gases is crucial for environmental monitoring and industrial applications.
- Existing spectroscopic methods often require complex setups or lack real-time analysis capabilities.
Purpose of the Study:
- To design and demonstrate a novel, automated, room-temperature laser spectrometer.
- To achieve high sensitivity and a wide dynamic range for trace gas detection.
- To enable rapid multicomponent analysis of gas mixtures.
Main Methods:
- Utilized difference-frequency generation in lithium niobate (LiNbO3) to produce tunable mid-infrared laser pulses.
- Employed a tunable external-cavity diode laser (795-825 nm) and a Nd:YAG laser (1064 nm).
- Integrated a 36-meter multipass cell for enhanced light-matter interaction and spectroscopic studies.
Main Results:
- Demonstrated on-line methane measurements with a dynamic range of 7 orders of magnitude (200 ppb to ~1%).
- Achieved computer-controlled multicomponent analysis of five trace gases and water vapor within 90 seconds.
- Attained a minimum detectable absorption coefficient of 1.1 x 10(-7) cm(-1) with a 60-second averaging time.
Conclusions:
- The developed laser spectrometer is a compact, automated, and highly sensitive instrument for trace gas analysis.
- The system enables ppb-level detection limits for numerous important gases.
- This technology has significant potential for real-time environmental monitoring and scientific research.
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