Optical feedback linear cavity enhanced absorption spectroscopy
- Resource Type
- Authors
- Adam J. Fleisher; Gang Zhao; Weiguang Ma; Jianfei Tian; Suotang Jia
- Source
- Opt Express
- Subject
- Time delay and integration
Materials science
Absorption spectroscopy
Spectrometer
business.industry
Phase (waves)
Laser
Article
Atomic and Molecular Physics, and Optics
law.invention
Optics
law
Reflection (physics)
business
Spectroscopy
Diode
- Language
- ISSN
- 1094-4087
A simple and universal technique for performing optical feedback cavity enhanced absorption spectroscopy with a linear Fabry-Pérot cavity is presented. We demonstrate through both theoretical analysis and experiment that a diode laser can be sequentially stabilized to a series of cavity modes without any influence from the direct reflection if the feedback phase is appropriately controlled. With robust handling of the feedback phase and help from balanced detection, a detection limit of 1.3 × 10−9 cm−1 was achieved in an integration time of 30 s. The spectrometer performance enabled precision monitoring of atmospheric methane (CH4) concentrations over a time period of 72 h.