Stabilized (3)He-(20)Ne transverse Zeeman laser

Tuning characteristics of power, intramode beat frequency, and polarization of 633-nm internal mirror lasers filled with natural Ne or (20)Ne are studied. It is found that the tuning curve of a polarization signal is S-shaped for the natural Ne laser, whereas that of the intramode beat frequency is S-shaped for the (20)Ne laser. The characteristic parameters of the tuning curve of the intramode beat frequency are determined. The axial modes of a (3)He-(20)Ne laser are collapsed into one by a transverse magnetic field and frequency stabilized by cooling the laser tube with a fan to keep the intramode beat constant. Frequency fluctuation of 3 x 10(-10) is obtained by the Allan variance analysis for the integration period range of 0.1-100 sec. Absolute accuracy and interinstrumental reproducibility of stabilized wavelengths can be expected for a (3) He-(20)Ne transverse Zeeman laser stabilized at the central frequency of the intramode beat.