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

[18a-Z06-10] Elucidation of the Third Harmonic Generation Mechanism in Air

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

Keywords:third harmonic generation, nonlinear optics

It has been known that the third harmonic generation from air undergoes a complex generation process, but no detailed study has been conducted so far in relation to the intensity dependence, which is a fundamental observable. In this study, we measured the intensity dependence and spectrum of the third harmonic at different focusing distances, and found that the experimental results changed depending on the focusing distance. We succeeded in reproducing these experimental results by numerical calculations, and clarified the relationship between the generation process of the third harmonic and its intensity dependence.