Presentation Information
[16p-WL2_301-3]Focusing of terahertz wave based on photo-Dember effect
〇Hiroaki Shirasaka1, Victor Isao Iwanaga1, Seigo Ohno1 (1.Tohoku Univ.)
Keywords:
terahertz,photo-Dember effect,focusing
This presentation reports on the generation of THz wave based on the photo-Dember effect and its utilization for the THz beam focusing. By shaping the pump beam into a ring and irradiating it onto a semiconductor crystal, a THz wave generated by photo-Dember effect is expected to be focused with High-NA at the center of the ring. In the experiment, a femto second laser pulse beam was shaped into a ring by an axicon lens and it was focused and irradiated onto an InAs substrate. By measuring the spatial distribution of beam diameter of a generated THz wave using knife-edge method, the focusing effect at a position away from a crystal edge was confirmed.