Related Experiment Videos
Cavity-enhanced spectroscopy in fiber cavities.
George Stewart1, Kathryn Atherton, Brian Culshaw
1Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow G1 1XW, Scotland. g.stewart@eee.strath.ac.uk
Optics Letters
|March 10, 2004
Summary
Active fiber cavities offer superior ring-down times compared to passive ones, enabling enhanced sensitivity for spectroscopic methods. This advancement allows for greater cavity enhancement and broader applications in scientific research.
Area of Science:
- Optics and Photonics
- Spectroscopy
- Cavity Ring-Down Spectroscopy
Background:
- Passive fiber cavities have demonstrated ring-down times of approximately 2 microseconds.
- Operation of passive cavities is limited to weak evanescent wave interactions.
- Active cavities offer potential for improved performance and broader applicability.
Purpose of the Study:
- To compare the relative merits of passive and active fiber cavities for ring-down applications.
- To investigate the use of amplifiers in active cavities for loss compensation.
- To explore the potential for enhanced sensitivity in ring-down measurements.
Main Methods:
- Utilized active fiber cavities with amplifiers for loss compensation.
- Employed open-path micro-optic cells.
- Investigated gain-clamped cavities for extended ring-down times.
Main Results:
- Achieved ring-down times of tens of microseconds, extendable to several hundred microseconds in gain-clamped cavities.
- Demonstrated the feasibility of using active cavities with amplifiers for loss compensation.
- Identified relaxation oscillations and system drift as limitations to accuracy and repeatability.
Conclusions:
- Active fiber cavities provide significant advantages over passive cavities for ring-down measurements.
- A cavity enhancement of 2 orders of magnitude is realistically achievable.
- Combining ring-down techniques with established spectroscopic methods can further enhance sensitivity.