High-Sensitivity Detection of the Off-Resonant Magnetic Birefringence of Gases
| Autor: | Yoshitaka Takubo, Morisato Namikawa, Kazuyuki Muroo |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | The Review of Laser Engineering. 27:416-420 |
| ISSN: | 1349-6603 0387-0200 |
| Popis: | The light-ellipticity change ψ caused by the off-resonant magnetic birefringence of gases (O2, N2, Ar) wasmeasured with a high-sensitivity polarimeter. In order to reduce background noise, we improvedthe extinctionratio of the polarimeter by using high-quality optical elements and adjusting the diameter of the light beam.The extinction ratio of 3×10-10 was then obtained. The measured value of ψ for Ar, which hadthe smallesteffect of magnetic birefringence among the three gases, was (1.1±0.3) ×10-9 under the following experimental conditions: light wavelength: 0.79 μm, pressure: 1.3×105 Pa, temperature: 296 K, magnetic field: 7 kG, optical path length: 5 cm. The minimum value of ellipticity change that could be detected was 3×10-10 at 1-mW incident-light intensity for the quantum efficiency of a light detector of 0.03 and a photon detection time of 16128s. The sensitivity attained in the experiment was in agreement with the theoretical value expected at theshot noise limit. |
| Databáze: | OpenAIRE |
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