[21a-W321-1~12] 3.7 Laser processing

[21a-W321-1] Ultrafast laser processing inside a diamond single crystal and dynamics after photoexcitation

〇Masaaki Sakakura¹, Takuro Okada², Vibhav Bharadwaj³, Belen Sotillo³, Shane Eaton³, Roberta Ramponi³, Ali Serpenguzel⁴, Ulas Gokay⁴, Yasuhiko Shimotsuma², Kiyotaka Miura² (1.Kyoto Univ. SACI, 2.Kyoto Univ., 3.Politec. Milano, 4.Koc Univ.)

Keywords:bulk laser processing,time-resolved transmission optical microscope,diamond

In this study, we investigated modification inside diamond induced by irradiation with tightly focused femtosecond laser from the observation of dynamics after photoexcitation. Although the transient transmission optical microscope images after photoexcitation in the time range from picoseconds to nanoseconds were similar after single pulse irradiation and double pulse irradiation with a time difference of picoseconds, permanent modification occurred only by double pulse irradiation. We speculated that laser pulse was tightly focused in diamond and photoexcitation occurred in a smaller volume in the case of double pulse irradiation.