transmissivities as well as relative phase shifts. These In this paper, the author analyzes the coupling of the results are then used to calculate the splitting in the two oppositely directed traveling waves in a ring reso- oscillation frequency and intensity of the ring laser. nator due to the photorefractive effect. The nonlocal response of the crystal, which gives rise to the asym- \\w Mode Coupling in a Ring Resonator metrical coupling of the waves, results in unequal We now consider ^ wave tion in a ri res . transmissivities as well as unequal phase shifts when the onator ^ us focus Qur atte F nt £ n * to the region