Fluctuation theory of detuned single mode laser.

The effect of detuning on the linewidth of photon intensity correlation and the spectral linewidth is studied. This can be done by taking into account a general canonical momentum of the field strength in the fluctuation Hamiltonian. Detuning mainly affects the linewidths via threshold shift, but also explicitly by a reduction of the linewidths by $$(1 + \tilde \Delta ^2 )^{ - 1}$$ ( $$\tilde \Delta$$ proportional to detuning). [ABSTRACT FROM AUTHOR]