[11a-N321-1~11] 3.7 Laser processing

△ [11a-N321-5] Development of Time-Resolved Digital Holography System for Detail Observation in Single-Pulse Laser Ablation

〇(D)Shotaro Kawano¹, Miu Tamamitsu¹, Haruyuki Sakurai², Kuniaki Konishi¹, Takuro Ideguchi¹, Junji Yumoto¹, Makoto Kuwata-Gonokami¹ (1.Graduate School of Science, The Univ. of Tokyo, 2.ISSP, The Univ. of Tokyo)

Keywords:laser processing, time-resolved complex optical field imaging, time-resolved digital holography

Time-resolved digital holography (TRDH) enables us to visualize the process of single-pulse laser ablation as a time-resolved image of amplitude and phase of the probe pulse. Using this technique, it has been attempted to observe the structural change of materials by laser ablation directly. This study has developed a diffraction-grating-based common-path shearing interferometer and TRDH optical system with sufficient spatial resolution and phase precision for that structural change. This system allows us to observe laser ablation dynamics as a time-resolved transmittance and optical-phase-delay (OPD) image with high OPD precision. We have demonstrated the proof of concept of this system.