[1P01-52] Poster Presentation

[1P47] Investigation of defect formation by femtosecond laser irradiation on zinc oxide

*Haruto Miura¹, Xi Yu², Yuma Takeda¹, Fumihiro Itoigawa¹, Shingo Ono¹ (1. Nagoya Institute of Technology, 2. Tokyo University of Science)

Zinc oxide (ZnO) has been actively researched for various applications in ultraviolet (UV) and visible optical regions. Moreover, ZnO-based devices were also reported as emitters of terahertz (THz) waves beyond the UV–visible region. In our work, the surface of the ZnO substrate was irradiated by a single femtosecond laser pulse with various energy. Surface cleavages along the crystalline were observed and quantitatively analyzed by a three-photon absorption (3PA) model. Besides that, the cleavage-melt shift was observed when more than four pulses were irradiated to the cleavage surface. Besides, to improve the transmittance of ZnO-based THz components, we fabricated moth-eye structures on ZnO substrate using femtosecond laser processing. Undesired deterioration of transmittance was observed according to the THz Time-Domain Spectroscopy. By annealing such laser fabricated ZnO surface to decrease, a remarkable transmittance improvement was achieved in the THz region.