Improved cross polarized wave generation with an aperture.

A cross polarized wave (XPW) generation experiment with double BaF₂ crystals in air was demonstrated with 120 µJ input pulse. A circular aperture was used to truncate the near field profile of the input beam and remove the outer part of the beam, and circularly symmetric beam profiles were generated at the BaF₂ crystal positions. The measured focal spot size was close to the diffraction limit, and the energy stability of XPW was improved from ∼1.89% (without the aperture) to ∼0.67% (with the aperture). [ABSTRACT FROM AUTHOR]