Chinese Optics Letters, Volume. 23, Issue 11, (2025)
Fabrication of nano-holes with tunable axial morphology via ring-lens-tailored Bessel beams [Early Posting]
This paper presents a laser-based technique for fabricating nano-holes with tunable axial morphology on fused silica using ring-lens-tailored Bessel beams. Unlike conventional axicon-based Bessel methods, this approach effectively controls the beam’s axial intensity peak by simply adjusting the ring-lens radius (R). By combining theoretical simulation and experimental validation, we demonstrate that the nano-hole morphology can be precisely tuned by modulating the beam’s initial energy peak. A taper entrance can be formed, with the taper angle effectively controlled within 52° by adjusting R from 1.25 to 2.50 mm. When R exceeds 2.50 mm, the axial energy distribution becomes uniform and leads to the disappearance of the taper, resulting in a standard cylindrical hole and offering a clear process window for controlling the nano-hole morphology. This single-pulse ablation method advances precision nano-manufacturing by enabling the efficient fabrication of customized nano-holes, with potential applications in photonics, microfluidics and other nano-engineering fields.