Simultaneous spatial and temporal walk-off compensation in frequency-doubling femtosecond pulses in beta-BaB2O4

摘要

We experimentally demonstrate the benefits of simultaneous compensation of spatial and temporal walk-off in frequency doubling of 800-nm 250-fs pulses, using three active and two compensating beta-BaB2O4 crystals. The compensating crystals reverse both birefringent and group-velocity walk-off, resulting in a factor-of-4.5 improvement in doubling efficiency relative to one of the active crystals while maintaining the short pulse duration and the symmetric spatial profile that are characteristic of the single crystal. (C) 1998 Optical Society of America. [References: 11]