Accession Number : AD0614360

Title :   HANLE EFFECT IN THE HE-NE LASER,

Corporate Author : LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF

Personal Author(s) : Culshaw,W. ; Kannelaud,J.

Report Date : 13 MAY 1964

Pagination or Media Count : 13

Abstract : The effect of small magnetic fields on the degenerate levels of the 1.153-micron He-Ne laser transition is considered in the region where the transitions overlap and coherence is imparted by the excitation and inducedemission processes. Perturbation equations for the phenomena are solved by a small-signal approximation, and the probability amplitudes summed coherently to give the resultant intensity and polarization changes. For a symmetrical disposition of the laser frequency with respect to the Zeeman transitions, the polarization remains linear until the states separate beyond the natural linewidth, but rotates with increasing magnetic field. Rotations around 45 degrees are indicated for axial and transverse magnetic fields less than one gauss. With the laser frequency asymmetric with respect to the transitions, elliptical polarization occurs. Investigations on a short planar laser show that such a rotation does take place when small axial magnetic fields are applied and that the polarization remains linear. Some variation with the rf level of excitation is encountered, and there are similar effects at a higher value of dc magnetic field. Studies with sawtooth and ac magnetic fields show the modulation and harmonics which result when the periodic rotation is passed through an analyzer. The separation beyond the natural linewidth is indicated by the appearance of circularly polarized beats at the extremes of the ac fields. The rotation consistently occurs with the laser tuned near the line center and operated well above threshold. (Author)

Descriptors :   (*LASERS, MAGNETIC FIELDS), (*HELIUM, LASERS), (*NEON, LASERS), (*EXCITATION, LASERS), MAGNETIC RESONANCE, POLARIZATION, ELECTRON TRANSITIONS, PERTURBATION THEORY, GASES

Distribution Statement : APPROVED FOR PUBLIC RELEASE