Stabilization Of Actively Q-Switched Lasers

A Q-switched laser comprising:

• a) a resonant cavity, containing therein a gain medium;
• b) a means for pumping the gain medium to increase an optical gain within the gain medium to produce an optical circulating power at a fundamental optical frequency with a cavity round trip time within the resonant cavity;
• c) a signal generator producing a gate signal having a gate width, and modulated at a pulse repetition frequency;
• d) an optical switch within the resonant cavity, responsive to the gate signal received from the signal generator to change the optical switch from a high loss state to a low loss state for a duration of the gate width for producing an optical pulse with an optical pulse width;
• wherein in the high loss state, energy accumulates within the gain medium to produce an initial optical gain, while the optical circulating power approaches an initial optical circulating power;
• and
• wherein in the low loss state, the optical circulating power increases to a peak optical circulating power, thereafter decaying as the energy accumulated within the gain medium diminishes and the optical gain is depleted;
• e) a nonlinear coupler within the resonant cavity for converting a portion of the optical circulating power at the fundamental optical frequency into a converted optical power, and having a nonlinear coupling level such that a gain fluctuation insensitivity condition is provided,
• wherein the converted optical power has a converted optical frequency with a converted optical pulse width;
• and
• f) a means for coupling the converted optical power out of the resonant cavity.