Properties of the Light from the Single Axial Mode Laser Degenerated by Transverse Magnetic Field

Abstract

The properties of the light of single longitudinal mode obtained from a laser subjected to a transverse magnetic field giving rise to the Zeeman separation equal to the longitudinal mode interval, are studied by means of the polarization analysis and optical beating techniques. The lasers studied are internal mirror type of 26-28cm cavity length, and oscillate with 2-3 longitudinal modes under normal conditions.
The light thus obtained was found to be composed of two almost linear orthogonally polarized components with different frequencies. The frequency difference between the two components differs from one tube to another and changes with the magnetic field and the tuning of the cavity. The frequency difference normally stays within the range of a few hundred kHz. The frequency difference as well as the wavelength of the laser oscillation can be stabilized by tuning the cavity referring to the polarization of the light. It was also found that laser oscillation of a single frequency can be obtained when the laser tube is set at a particular azimuthal angle to the magnetic field.