CAVITY FOR SOLID STATE MICRO-LASER HAVING OPTIMIZED EFFICIENCY AND MICRO-LASER USING THE SAME

Japanese Patent JP3798053

B2

PROBLEM TO BE SOLVED: To form a pumping beam and a laser beam regardless of a thermal effect, by causing the dimension of the pumping beam to be not greater than the dimension of the laser beam in an active medium of reflection means. SOLUTION: An entrance surface 14 and an exit surface 16 are recess-shaped, and spherical mirrors are formed on the entrance and exit surfaces by depositing a dielectric film thereon. Each of the entrance and exit mirrors has a radius of curvature which is so determined that the dimension of a pumping beam in an active material 12 is not greater than the dimension of a laser beam in the same material (the so-called overlap condition). When a pumping beam 22 is completely included in a laser beam 24 (satisfactory overlap), the whole pumping energy is absorbed in an effective volume of the laser. For a certain period from the time when a waveguide effect due to a gain and a parasitic thermal effect due to heating by the pumping beam can be ignored, as soon as the energy is absorbed in the laser beam, the energy is related to a laser effect and can be generated regardless of the thermal effect.