ADVANCED SHIFTING ALGORITHM FOR PROLONGING THE LIFE OF AN OPTICALLY NONLINEAR CRYSTAL

摘要

In a shifting algorithm for an optically nonlinear crystal (24) arranged to frequency- convert a beam of radiation, the location of one or more defects in the crystal (24) is recorded as an exclusion zone. The location of the beam (32) is stepped incrementally over a surface of the optically nonlinear crystal around a closed or open loop path in increments less than a beam dimension. The path is arranged such that the beam does not enter the exclusion zone.