Characterization of a diode-pumped cw high-power all solid-state laser at 266 nm

The DeltaConcept is an actively stabilized unidirectional cavity design with a minimum number of optical components-two mirrors and one prism. The symmetrical Brewster-angled beam path through the prism guarantees minimum losses and hence maximum power enhancement and efficiency. The first cw UV laser at 266 nm is accomplished by frequency doubling the 532 nm output of a diode-pumped Nd:YAG laser with the actively stabilized unidirectional ring cavity based on the DeltaConcept. The excellent performance of this 266 nm laser like UV power stability and high beam pointing stability results mainly from the unique features of the DeltaConcept. Also the compact and rugged design of the whole 266 nm laser by hermetic double-sealing of both the DPSSL pump source and the quadrupling stage results in an additional protection of the BBO crystal against environmental influences and reduces the effort in alignment of the whole system. This stable continuous wave UV laser will find versatile applications in both industrial and scientific fields including disc-mastering, wafer inspection, UV photolithography, micromachining, holography as well as absorption and fluorescence spectroscopy.