Detection of molecules by the resonant Voigt effect spectroscopy

以窄带染料激光器为光源，研究了火焰中OH自由基的共振Voigt效应（横向磁场诱导的光学各向异性）。椭圆偏振光被调谐到<Q_1>电子跃迁带&lt;A^2&gt; &lt;SIGMA^+&gt;（v '= 1）- &lt;X^2&gt;（v”= 1）中的（1）和&lt;Q_（21）&gt;（1）线<PAI_i>。用偏角双折射棱镜分析了光通过火焰后的偏振态。的Voigt效应信号的测量配置文件进行了解释的基础上的分子塞曼效应。通过调整光的椭圆率和检偏器的偏置角，在上述谱线的检测中，Voigt效应的信噪比（SNR）比估计的吸收SNR提高<about>了&lt;10^2&gt;倍。这种技术提供了一种替代的分子光谱学方法。

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.