Time-spectrum characteristics of g of double frequency Zeemen He-Ne laser and its applications

In terms of the typical structure in frequency spectrum of Zeemen He-Ne laser, a time-spectrum formula of g (the degree of first order temporal coherence) of the double frequency Zeemen laser was derived, considering of the longitudinal mode frequency drift. The results show that: (1) because of the effect of line width, the time coherence of g has a variation period, (2) the variation of time spectrum of g is relative to frequency drift of double frequency mode; (3) the time spectrum characteristics of g can be used in the measurements of the laser parameters or the frequency stabilization of the double frequency laser.