Printable surface hologram via nanosecond laser ablation

[摘要] Holography plays a significant role in applications such as data storage, light trapping, security, and biosensors. However, traditional fabrication methods remain time-consuming, labour-intensive, complex and costly, limiting the extensive and massive production of holograms. In this thesis, a single-pulse laser ablation strategy was used to write surface gratings and zone plates. A 5 ns high-energy green laser pulse was utilized to form interference patterns on ink-based (150 nm thickness) and gold-based (4 nm thickness) substrates. The holographic recording process was completed within seconds. The periodicities for ink-based and gold-based gratings are 2.6 μm and 820 nm, respectively. The optical characteristics of the interference patterns have been computationally modeled, and diffraction patterns were observed from the fabricated grating holograms by different monochromatic wavelengths. In addition, the asymmetric zone plate was fabricated on 4.5 nm gold layer, and a well-ordered rainbow pattern with a significant diffraction angle of 32° was measured from the normal incident. An power meter experiment was also conducted to determine the diffraction efficiency of 0.8% by white light illumination. Handwritten signatures and 3D coin images were demonstrated to support the utilization of single laser ablation approach, and the fabrication methodology holds great potential in applications for optical devices.

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Mechanical Engineering

[关键词] T Technology;TJ Mechanical engineering and machinery