HIGHLY EFFICIENT 2ND-HARMONIC GENERATION OF ULTRAINTENSE ND-GLASS LASER-PULSES

Second-harmonic conversion efficiencies of 80% for type I KDP crystals and 70% for type II have been demonstrated with 500-fs, 1.053-mu m laser pulses at intensities as high as 400 GW/cm(2). The results are generally in good agreement with simulations and indicate that self-phase modulation and cross-phase modulation may be significant. For type II conversion with a predelay between the input o and e waves, some evidence is obtained of pulse shortening to similar to 100 fs.