Second-order coherence g(2) (τ) and its frequency-dependent characteristics of a two-longitudinal-mode laser

Abstract.

 The degree of second-order coherence g ⁽²⁾(τ) and its frequency-dependent formula of a two-longitudinal-mode laser (simply called two-mode laser) are derived from the quantum theory of light. The quasi-periodicity, frequency-dependent characteristics and photon statistics properties of g ⁽²⁾(τ) are analysed theoretically. It is found that for a two-mode laser field there exists the effect of photon anticorrelation and the g ⁽²⁾(τ) can be measured by the optical interference method. The frequency-tuning characteristics of g ⁽²⁾(τ) in the two-mode laser field is also analysed. It is shown that the frequency-dependent characteristics of g ⁽²⁾(τ) can be applied to frequency and power stabilization of the two-mode laser and the measurement of two-mode laser linewidth Δν_D and the frequency width δν_h of each longitudinal-mode, respectively.