| Title |
Ablation of black-Si by (Gauss-)Bessel femtosecond laser beams |
| Authors |
Zheng, Nan ; Huang, Hsin-Hui ; Le, Nguyen Hoai An ; Katkus, Tomas ; Mu, Haoran ; Ng, Soon Hock ; Ranaweera, Thumula ; Gailevičius, Darius ; Stonytė, Dominyka ; Juodkazis, Saulius |
| DOI |
10.1016/j.optlastec.2025.114343 |
| Full Text |
|
| Is Part of |
Optics and laser technology.. London : Elsevier Ltd. 2026, vol. 193, part. B, art. no. 114343, p. [1-10].. ISSN 0030-3992 |
| Keywords [eng] |
ablation ; axicon ; black Si ; threshold of ablation |
| Abstract [eng] |
Laser machining and modification of black-Si (b-Si) by femtosecond laser Gaussian (G-) and Gauss-Bessel (GB-) beams are compared at a wavelength of 1030 nm. The GB-beam was generated using a diffractive axicon lens and 10× demagnification optics. It was found that modification of b-Si well below (a factor ∼50×) the single pulse ablation fluence of 0.2 J/cm2 was possible, corresponding to ablation/melting of nano-needles. The width of modification was almost independent of pulse energy/fluence and had a width of 1/e2-intensity profile at the melting regime. For the GB-beam, the smallest width of laser modification at ∼0.2 J/cm2 threshold (at the center core) was close to the FWHM of the core of the GB-beam. The aspect ratio of the ablated groove on the surface of b-Si made by GB-beam was twice as large –up to 8– compared to that achievable with G-beam, and it was at a lower fluence of ∼4 J/cm2 (∼50× reduction). Reflectivity of two-side nanotextured b-Si on plasma-thinned 70-µm thick Si was strongly reduced in the near-IR range, reaching transmittance >95% at 1.7–2.1 µm wavelengths. |
| Published |
London : Elsevier Ltd |
| Type |
Journal article |
| Language |
English |
| Publication date |
2026 |
| CC license |
|
