Frequency-locking of a CW dye laser to absorption lines of neon by a Faraday filter

Single-mode CW oscillations at absorption lines of neon from the
1s
states to the
2p
states were achieved by inserting a Faraday filter in an argon-laser-pumped dye laser cavity without any other wavelength selective elements. The oscillations at absorption lines were selected by choosing adequate values of the filling pressure of a neon discharge tube and a magnetic field strength. The oscillation frequency shifted with the increase of the magnetic field strength toward higher frequency in the center region and toward lower frequency on the wing of the absorption line, which was found to be due to the isotope effect. Good agreement was found between the experimental results and the theoretically calculated feature of the Faraday filter.