| 摘要 |
PURPOSE:To enable high output generation that the divergence angle is small by generating a laser beam of only one-way components efficiently by means of a laser medium consisting of plural solid elements or a solid element, through which the laser beam passes plural times, within a ring-shaped unstable resonator. CONSTITUTION:Three solid elements 1 forms a laser medium, being excited, respectively, by the direct lights from exciting light sources 3 and the reflected lights from condensing and reflecting mirrors 5. On the other hand, the laser beams 9 and 10, which are generated in an unstable resonator composed, in ring shape, of an outlet mirror 6, condenser lenses 100 and 101, and full reflecting mirrors 2, are amplified each time they make rounds, and when they become certain sizes or more, one part each of them is emitted as a laser beam 11. The laser beam is enlarged for beam diameter by the condensing element 101, after being converged through the condensing element 100, and is collimated into a parallel light. Hereupon, a space filter 102 having an opening is inserted near the condensing point inside two condensing elements, and if cutting the circumferential part with it, only the good quality of beams can make round inside the resonator. |
