A 5 MHz beat frequency He-Ne laser equipped with bireflectance cavity mirror

This paper describes a He-Ne dual-frequency laser equipped with a bireflectance cavity mirror. This is based on the principle that when the incident light is perpendicular to the mirror, the phase delays of the reflective light along the mirror's fast and slow axes are different, because of the photoelastic effect. The mode coupling is reduced using transverse Zeeman effect so that two linear and orthogonal polarization components with 5 MHz beat frequency are generated. Experiments are then used to examine the effect of the magnetic field's direction on the dual-frequency and the polarization property of the laser. The expanded uncertainty of wavelength in vacuum is 1x10(super-7) with a frequency stabilization of 6.6x10(super-10). (Original abstract - amended)