Investigations on Melting and Welding of Glass by Ultra-short Laser Radiation

Abstract

Top down technique of interfering femtosecond laser processing was applied to generate new nanomaterials such as nanocrown, nanomesh, nanobelt, and dual periodic structure. In the case of nanocrown, whiskers are standing at the edge of a nanohole. The width of a whisker was just 80 nm. A nanohole array structure generated by interfering 4 beams was applied to a spatial filter as a base material for the growth of photo-polymerizing polymer, and polymer nanobump array was generated. Dual periodic structures were generated by multiple shots, and bimetallic nanobelt was generated from bilayer thin film. Processing of fiber film was tested.

Femtosecond laser three-dimensional micro- and nanofabrication

“…Thus, an ultrafast laser with a repetition rate higher than several hundred kilohertz can improve welding performance, such as the process efficiency and bonding strength, due to the heat accumulation effect. 13,176,182,186 A picosecond laser is superior to a femtosecond laser in terms of higher joining efficiency by its higher nonlinear absorptivity. 182 The nonlinear absorptivity of an ultrafast laser is specifically associated with the combination of multiphoton ionization and subsequent avalanche ionization.…”

“…Since then, both femtosecond lasers and picosecond lasers have been extensively used to bond both the same type of glass substrates, including fused silica, 14,175,[177][178][179][180][181] borosilicate glass, 13,177,[182][183][184][185][186] soda-lime glass, 187 non-alkali aluminosilicate glass, 176 and photosensitive Foturan glass. 40,[188][189][190] Dissimilar glass substrates such as fused silica/borosilicate glass, 41,179,181,191,192 optical fiber/glass slide, 193 spherical glass bead/float glass, 194 and some other glasses 195,196 have also been fused using the same technique.…”

Micromanufacturing: A review—part II

“…Laser MJ has many attractive applications in joining nonmetallic materials such as glass, silicon and plastics. 124 These nonmetallic materials are generally joined by transmission welding. The wavelength of laser source is chosen in such a manner that the substrate material acts as transparent and ultra-short pulse (femtosecond) laser serves this purpose.…”

Optical bonding reinforced by femtosecond laser welding

“…Several strategies were proposed to induce appropriate contact, such as using a clamping device [4][5][6][7][8][9] and relying on the van der Waals interactions between materials [11][12][13][14][15]. This kind of contact technique limits the potential size of a welded region.…”

“…Filamentation and nonlinear absorption processes induced by focused fs laser pulses [1][2][3] at the interface between two transparent dielectric materials has proven to create joined regions with unique mechanical and thermal properties [4][5][6][7][8][9][10][11][12][13][14]. Furthermore, this technique is applicable to both similar and dissimilar material combinations as long as one of the materials is transparent to the laser wavelength, which may be adjusted accordingly [5,6,[15][16][17][18].…”