We present an experimental investigation of the interaction of highly coherent far-infrared radiation with a paramagnetic gas of NO<sub>2</sub> molecules in the presence of magnetic fields. Depending on the characteristics of the magnetic field and on other experimental parameters, we can observe a continuous transition from a Zeeman effect regime to a Faraday (or magnetic rotation) effect regime. The results obtained are compared with theory, and calculations are performed with a view to use of the Faraday effect for more-sensitive spectroscopy in the far-infrared region.
© 1999 Optical Society of America
(020.0020) Atomic and molecular physics : Atomic and molecular physics
(020.7490) Atomic and molecular physics : Zeeman effect
(300.0300) Spectroscopy : Spectroscopy
(300.6270) Spectroscopy : Spectroscopy, far infrared
S. Viciani, P. De Natale, L. Gianfrani, and M. Inguscio, "Magnetic-field effects on molecular transitions in the far-infrared region: prospects for more-sensitive spectrometers," J. Opt. Soc. Am. B 16, 301-307 (1999)