J4 ›› 2015, Vol. 32 ›› Issue (2): 198-204.

• Nonlinear Optics • Previous Articles     Next Articles

Second harmonic generation of flat-topped beams in single and twin BBO crystal

LIU Qi, WANG Yan, WANG Xiao-yan, BAI Li-hua, ZHANG Hui-fang   

  1. Department of Physics, Shanghai University, Shanghai 200444, China
  • Received:2014-04-23 Revised:2014-05-30 Published:2015-03-28 Online:2015-03-17

Abstract:

The coupled wave equations for second harmonic generation of flat-topped beams propagating in birefringent uniaxial anisotropic medium are presented. Based on them, specific physical models of single and twin BBO have been established and numerical computation has been carried out. The influences of beam waist, medium structure on second harmonic generation are analyzed. The calculation results indicate that a wider waist can make a better phase matching, so the second harmonic beam will maintain the flat-topped property better but with a lower intensity and twin crystal can eliminate beam walk-off in some way.

Key words: nonlinear optics, second harmonic generation of flat-topped beam, numerical computation, twin crystal