[18a-Z06-1~11] 3.6 Ultrashort-pulse and high-intensity lasers

[18a-Z06-11] Harmonic Generation with Counter-Rotating Circularly Polarized Two-Color Beams at the Tight Focusing Limit

〇Wataru Komatsubara¹, Kuniaki Konishi¹, Junji Yumoto¹, Makoto Kuwata-Gonokami¹ (1.Graduate school of Science, The Univ. of Tokyo)

Keywords:harmonic generation, two color, circular polarization

In the harmonic generation at the the tight focusing limit (TFL), it has been known that sum frequency generation is forbidden and difference frequency generation is allowed due to the phase matching condition. However, there has been no study of polarization control at the TFL, and the interaction between the polarization selection law and TFL has not yet been clarified. In this study, we performed experiments and numerical calculations of harmonic generation at TFL, and found that a small deviation in the ellipticity of the incident electric field is amplified by the phase matching, and causes results that seem to contradict the polarization selection law.