Detection of molecules by the resonant Voigt effect spectroscopy

点击翻译按钮获取中文摘要

The resonant Voigt effect (optical anisotropy induced in a transverse magnetic field) was investigated for OH radicals in a flame with a narrow-band dye laser as a light source. Elliptically polarized light was tuned to the <Q_1> (1) and <Q_(21)> (1) lines in the electronic transition band <A^2> <SIGMA^+> (v'=1)- <X^2> <PAI_i> (v"=1). The light polarization after passing through the flame was analyzed with an angle-offset birefringent prism. The measured profiles of the Voigt effect signal were interpreted on the basis of the molecular Zeeman effect. By adjusting the light ellipticity and the analyzer offset angle, the signal to noise ratio (SNR) of the Voigt effect was improved over the estimated absorption SNR by a factor of <about> <10^2> in the detection of the above lines. This technique offers an alternative method of molecular spectroscopy.