Physical mechanism of asymmetric bistable and dynamically unstable emission with low second threshold in Raman lasers

Bistable and dynamically unstable emission from a single-mode homogeneously broadened Raman laser is shown to arise from laser- and pump-field induced distortion and displacement of the dispersion profile associated with the laser gain. These features occur for broad cavity tuning to the low-frequency side of gain center, the threshold for dynamical behavior, being as low as the first lasing threshold. Results of this analytic treatment are in exact agreement with earlier numerical analysis. © 1990 The American Physical Society.