Measuring finesse and gas absorption with Lorentzian recovery spectroscopy
| Autor: | John A. Lipa, Shailendhar Saraf, Si Tan, Paul Berceau |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Heterodyne
Materials science business.industry Physics::Optics Optical power Laser 01 natural sciences Atomic and Molecular Physics and Optics law.invention 010309 optics Laser linewidth Finesse Optics law Attenuation coefficient 0103 physical sciences Physics::Accelerator Physics 010306 general physics Spectroscopy Absorption (electromagnetic radiation) business |
| Zdroj: | Optics Express. 25:7645 |
| ISSN: | 1094-4087 |
| Popis: | In this paper we present a method for obtaining accurate finesse by recovering the Lorentzian profile of cavity resonances with a laser continuously locked to the cavity and apply it to weak gas absorption measurements. The technique was implemented on our noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) experimental setup. The measurement is performed in the cavity-locked regime, leading to high repeatability and easy automation. The technique involves locking the carrier to a fundamental mode of the cavity and sweeping a second set of sidebands across adjacent cavity modes. The Lorentzian line shape can be reconstructed through a measurement of the transmitted optical power of the auxiliary sidebands. The cavity finesse and gas absorption can then be extracted from these power measurements. The accuracy of our measurements was verified by comparing our results to those obtained with the cavity ring down technique. We demonstrate the use of the technique in spectroscopy by measuring the absorption coefficient of the R(14) line ofsup12/supCsup16/supO that has been well characterized by others. The gas absorption results obtained were consistent with other experimental measurements and theoretical calculations. |
| Databáze: | OpenAIRE |
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