摘要 |
A laser device for generating frequency-doubled laser pulses at maximum efficiency. A laser rod is optically pumped to radiate unpolarized light at 1.064 mu wavelength for transmission within a ring-type resonator defined by a flat mirror and a turning prism. The light from one end of the rod is linearly polarized by a beam splitter into two parallel beams of orthogonal components which are transmitted through an 0.532 mu output mirror, a frequency doubler phase matched for one component, and a Q-switch, to the turning prism for return along the beam of the other component to the beamsplitter. The output mirror, doubler and Q-switch are substantially ineffective during the pumping cycle, and because the component beam axes are reversed, the light does not return to the rod for stimulating light emission. After peak level pumping, however, the Q-switch is biased to rotate each component one quarter wavelength and return the components to combine and reenter the rod for stimulated light emission. The frequency doubler, now receiving high power radiation, transforms a portion of the returning 1.064 mu component to a 0.532 mu component which is then reflected out of the resonator by the output mirror.
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