Extremely regular periodic surface structures in a large area efficiently induced on silicon by temporally shaped femtosecond laser

Abstract

Femtosecond laser-induced periodic surface structures (LIPSS) have several applications in surface structuring and functionalization. Three major challenges exist in the fabrication of regular and uniform LIPSS: enhancing the periodic energy deposition, reducing the residual heat, and avoiding the deposited debris. Herein, we fabricate an extremely regular low-spatial-frequency LIPSS (LSFL) on a silicon surface by a temporally shaped femtosecond laser. Based on a 4 f configuration zero-dispersion pulse shaping system, a Fourier transform limit (FTL) pulse is shaped into a pulse train with varying intervals in the range of 0.25–16.2 ps using periodic π -phase step modulation. Under the irradiation of the shaped pulse with an interval of 16.2 ps, extremely regular LSFLs are efficiently fabricated on silicon. The scan velocity for fabricating regular LSFL is 2.3 times faster, while the LSFL depth is 2 times deeper, and the diffraction efficiency is 3 times higher than those of LSFL using the FTL pulse. The formation mechanisms of regular LSFL have been studied experimentally and theoretically. The results show that the temporally shaped pulse enhances the excitation of surface plasmon polaritons and the periodic energy deposition while reducing the residual thermal effects and avoiding the deposition of the ejected debris, eventually resulting in regular and deeper LSFL on the silicon surface.

Regular Periodic Surface Structures on Indium Tin Oxide Film Efficiently Fabricated by Femtosecond Laser Direct Writing with a Cylindrical Lens

“…Figure 2 shows a schematic diagram of the measurement setup to characterize the structural color of the samples from different viewing angles [ 18 , 29 ]. A wide spectral light source (a tungsten halogen lamp with a spectral range of 400–2200 nm) illuminated vertically on the sample surface, and structural colors were measured at different viewing angles using a CCD moving in the Y-Z plane (perpendicular to the LIPSS direction).…”

“…In the large variety of subfields related to ultrafast laser micro/nano-processing, laser-induced periodic surface structures (LIPSS) have received considerable attention over the past decades [ 9 , 10 ]. The formation of LIPSSs is a universal phenomenon observed on semiconductors, dielectrics, metals and thin films [ 2 , 5 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. According to the relationship between incident laser wavelength λ and the period of induced surface structures Λ , LIPSS can be classified as high spatial frequency LIPSS (HSFL, Λ < 0.5 λ ) and low spatial frequency LIPSS (LSFL, 0.5 λ < Λ < λ ) [ 5 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…The formation of LIPSSs is a universal phenomenon observed on semiconductors, dielectrics, metals and thin films [ 2 , 5 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. According to the relationship between incident laser wavelength λ and the period of induced surface structures Λ , LIPSS can be classified as high spatial frequency LIPSS (HSFL, Λ < 0.5 λ ) and low spatial frequency LIPSS (LSFL, 0.5 λ < Λ < λ ) [ 5 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. LIPSSs exhibit great potential for applications in many fields, such as structural colors [ 18 , 27 , 28 , 29 ], color-based anti-counterfeiting [ 30 ], superhydrophobicity [ 31 , 32 ] and birefringence [ 33 , 34 , 35 , 36 ].…”

High-Performance Birefringence of Periodic Nanostructures in FTO Thin Film Fabricated by IR-UV Femtosecond Laser

“…Femtosecond laser-induced periodic surface structures (LIPSS) have been studied extensively for many types of materials, such as metals, semiconductors, dielectric solids, and thin films [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Owing to its versatility and flexibility, femtosecond LIPSS has become an efficient processing technique for fabricating functional devices, for structural color, absorption and luminescence enhancement, and large-area gratings [15][16][17][18][19].…”

Laser Direct Writing of Dual-Scale 3D Structures for Cell Repelling at High Cellular Density

“…One of the most popular technologies for modifying the topography of a material is laser irradiation. Of particular interest for the present study, laser surface micro- and nanopatterning evolved into a standalone domain, with extensive applications [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The laser-generated micro- and nanostructures have been used for a wide variety of applications such as to modify the surface wettability [ 24 ] and to control cellular adhesion [ 25 ].…”