Time spectrum characteristics of g(1)(τ) 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 g1(τ) (the degree of first order temporal coherence) of the double frequency Zeemen laser is derived, considering of the longitudinal mode frequency drift. These research results show that:(1) because of the effect of line width, the time coherence g1(τ) has the variation of period τ0= 1/Δνolr,(2) the variation of time-spectrum of g1(τ) is relative to frequency drift of double frequency mode; (3) the time-spectrum characteristics of g1(τ) can be used in the measurements of the laser parameters or the frequency stabilization of the double frequency lasers.