Abstract: An optically-pumped solid state laser system having separate subsystems for cooling its gain medium and optical pumping assembly. The invention permits the operating temperatures of the gain medium and optical pumping assembly to be independently controlled, and permits a substantial increase in cooling efficiency as a result of independent control of coolant flow rates in the two cooling subsystems. In a class of preferred embodiments, the gain medium cooling subsystem includes a first channel through which coolant flows with relatively high flow rate and relatively low temperature (to maintain the gain medium at a desired low operating temperature), and the other cooling subsystem includes a second channel through which coolant flows with a relatively low flow rate and relatively high temperature. In one embodiment, the gain medium is a Holmium:YAG rod, and a Cerium doped glass tube surrounds the rod.

Abstract: A method and apparatus for minimizing damage to an optical fiber used as part of a laser radiation delivery system are disclosed. The apparatus includes the use of a spacer positioned adjacent the tip of the fiber to minimize the impact on the fiber tip of debris and vapor generated by exposure of a tissue target to high energy radiation. The end of the apparatus is configured to vent debris and vapor from the end of the tip to reduce damage. The fiber tip may also be annealed to enhance its resistance to damage. The method includes the step of spacing the fiber tip at a predetermined distance from the tissue target during exposure of the tissue target to laser radiation, and may include venting the debris created away from the fiber end. The method may further include the step of providing an annealed fiber tip.

Abstract: A method and device for preventing premature optics burn-out in a laser having a solid gain medium is provided. The invention involves preheating the gain medium by supplying power at a level which is sufficient to set up a thermal lens, yet insufficient to cause substantial production of laser light. In one approach, a simmer routine is overlaid on a ramp routine, so that the power supplied to the gain medium is gradually increased during the warm-up period.

Abstract: The subject invention relates to method of suppressing one of the counterpropagating intracavity pulses generated in a dye laser synchronously pumped by the output of a mode locked Q-switched pump laser. The method includes extracting a portion of one of the pulses generated in the cavity such that the other pulse experiences a greater effective gain. The pulse with the highest effective gain will dominate the other pulse and at the steady state only one pulse will exist in the cavity. In the preferred embodiment, a double pass acousto-optic cell is used to extract the both the unwanted pulse and, at a later time, the high energy, useful pulse. In this case, maximum efficiency is achieved by placing the dye cell at one of a number of well defined locations within the optical cavity.