Large-area straight, regular periodic surface structures produced on fused silica by the interference of two femtosecond laser beams through cylindrical lens

Abstract

Inhomogeneity and low efficiency are two important factors that limit the application of laser-induced periodic surface structures (LIPSSs), especially on glass surfaces. In this study, two-beam interference (TBI) of femtosecond lasers was used to produce large-area straight LIPSSs on fused silica using cylindrical lenses. Compared with those produced using a single circular or cylindrical lens, the LIPSSs produced by TBI are much straighter and more regular. Depending on the laser fluence and scanning velocity, LIPSSs with grating-like or spaced LIPSSs are produced on the fused silica surface. Their structural colors are blue, green, and red, and only green and red, respectively. Grating-like LIPSS patterns oriented in different directions are obtained and exhibit bright and vivid colors, indicating potential applications in surface coloring and anti-counterfeiting logos.

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

“…The formation of LIPSS by laser direct writing is a multi-pulse cumulative process, which greatly depends on the laser fluence and scanning speed [37,38]. In the following, the formation of LIPSS induced by the 515 nm fs laser and the phase retardance were studied by changing the laser fluence and scanning speed.…”

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

“…Compared with a common circular lens with the same focal length (focal spot diameter of 15 μm), the fabrication efficiency is 266 times higher. Moreover, the LIPSSs produced with a cylindrical lens are also more regular [ 29 , 36 ]. An electronically controlled half-wave plate was used to continuously rotate the direction of laser polarization.…”

“…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).…”

“…Based on the study of the LSFL formation mechanism and effects of the fabrication parameters, large-area extremely regular LSFLs with a diameter of 30 mm were prepared efficiently on the ITO thin film by femtosecond laser direct writing with a cylindrical lens [ 29 ]. The laser fluence was 0.66 J/cm 2 and scanning velocity was 3.0 mm/s, indicating that the interval between adjacent scanning lines was 1.5 mm and the number of cumulative pulses per spot was about five.…”

“…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 ].…”