Method of continuous motion for prolong usage of optical elements under the irradiation of intensive laser beams

摘要

A method and apparatus are described for prolonging the usage life of an optical element under the irradiation of an intensive laser beam. The method employs a continuous mechanical motion to enlarge the effective interaction area and the volume of the laser beam within the optical element. In an embodiment, the apparatus is used for harmonic generation of a laser beam within a BBO crystal. A motor is used to drive the BBO crystal mounted on a pair of translation slides. The crystal is moved on a circular path spiraling within a predetermined area while its optical axis remains in the same orientation in relation to a laser beam. The phase matching angle of the BBO is maintained during the movement, and the usage life of the BBO crystal is increased by many orders of magnitude.