M~2- MEASUREMENT AND IMPROVEMENT BY PHASE-CONJUGATION OF EXCIMER LASER RADIATION

摘要

Using the M~2- formalism for near Gaussian beams and the beam parameter product, the possibilities of improving the beam quality of excimer lasers modified for applications requiring small focal spots are examined. It is demonstrated that nearly diffraction limited radiation (M~2 = 1.3) can be extracted from a conventional XeCl-excimer laser equiped with transversal mode selecting apertures. Another application of the M~2- formalism is the characterization of the fidelity of phase-conjugating mirrors even for non-ideal lasers such as excimer lasers. Finally, the application of phase-conjugating mirrors in a master-oscillator-power amplifier with excimer lasers is discussed briefly.