ON THE THEORY OF RAMAN MASERS
Raman光激射器

In this article, the coupling equations of the laser, the first Stokes, the first anti-Stokes light, and the coherent phonon field are derived from the hamiltonian with the relaxation and dissipation terms introduced phenomenologically. The properties of these equations are analysed by adopting an approximation higher than the quasi-static approximation, provided the molecules are far from resonance. The threshold for a Raman Maser is obtained and the temporal behaviour discussed. It is shown that no additional threshold condition is required for the anti-Stokes components, i.e., the stimulated anti-Stokes radiations make their appearance as a matter of fact in the stimulated Raman effect. Under certain conditions, there exists only one stable equilibrium point, at which the Stokes and anti-Stokes light appear with equal intensity, when the Raman-active medium is pumped by an intensive laser beam. The effect of phonon relaxation and the behaviour of the Raman Maser with long lifetime phonons are discussed as well.