报告题目 (Title)：Laser Modification of Materials at Micro- and Nanoscale for Photonics and Information Technology（材料在微纳尺度的激光改性及其在光子学和信息技术的应用）

报告人 (Speaker)：Dr. Yuhao LEI (雷雨昊)（香港中文大学）

报告时间 (Time)：2024年11月27日(周三) 13:30-15:30

报告地点 (Place)：校本部 G313

邀请人 (Inviter)：戴晔

主办部门：理学院物理系

摘要 (Abstract)：

Ultrafast laser induced modification in transparent materials, in particular nanogratings in silica glass, has been used for the demonstration of optical components and for multiplexing optical data storage. However, relatively high transmission losses and low writing speeds limit their practical applications.

A new type of birefringent modification (type X) with ultra-high optical transmittance has been demonstrated in silica glass by using suitable ultrafast laser writing parameters. The randomly distributed anisotropic nanopores are responsible for the form birefringence and high transmission from infrared to ultraviolet range. Different optical elements with ultra-high efficiency were fabricated from the ultraviolet to the infrared range for phase and polarization shaping.

To increase the speed of data writing for 5D optical data storage, a single nano-lamella structure has been produced in the silica glass, requiring only a few ultrafast laser pulses to write. The achieved data writing speed of is up to MB/s and the potential data capacity is ~500 TB per disk.