A review on glass welding by ultra-short laser pulses

Abstract

Glass welding by ultra-short pulsed (USP) lasers is a piece of technology that offers high strength joints with hermetic sealing. The joints are typically formed in glass that is transparent to the laser by exploiting nonlinear absorption effects that occur under extreme conditions. Though the temperature reached during the process is on the order of a few 1000 °C, the heat affected zone (HAZ) is confined to only tens of micrometers. It is this controlled confinement of the HAZ during the joining process that makes this technology so appealing to a multitude of applications because it allows the foregoing of a subsequent tempering step that is typically essential in other glass joining techniques, thus making it possible to effectively join highly heat sensitive components. In this work, we give an overview on the process, development and applications of glass welding by USP lasers.

Taming Ultrafast Laser Filaments for Optimized Semiconductor–Metal Welding

“…Precompensating the nonlinear focal shift yields shear joining strengths up to 2.2 MPa. The strength values displayed in Figure 3b are comparable to those obtained with the laser welding technique in other material configurations [ 7–12 ] as well as with adhesive bonding. Insignificant strengths (⩽50 kPa) have been measured for nJ since the modification threshold of copper is not reached at these input pulse energies, as confirmed with scanning electron microscopy (SEM).…”

“…[ 1–4 ] While ultrashort laser pulses represent an extraordinary tool for clean material removal with applications in material processing [ 5 ] or nanosurgery, [ 6 ] they are also attractive for additive manufacturing as they offer the possibility of joining a wide variety of materials that are impossible to bond using standard welding procedures. Nowadays, ultrafast laser welding can be successfully applied in configurations such as glass–metal, [ 7 ] glass–semiconductor, [ 8 ] glass–glass, [ 9,10 ] polymer–polymer, [ 11 ] and, more recently, ceramic–ceramic, [ 12 ] yielding MPa shear joining strengths. Given that this order of magnitude is similar or even higher than the one that can be obtained with traditional bonding methods (e.g., adhesive bonding), laser welding is an attractive alternative to these as it shows no aging or degasification problem.…”

Surface Probing of Ultra‐Short‐Pulse Laser Filament Cut Window Glass and the Impact on the Separation Behavior

“…Following this last explanation, the high energy of the laser induces nonlinear optical effects, which leads to the Kerr effect and repeating cycles of self-and defocusing. [11][12][13][14] After each focusing cycle a plasma spot is generated, creating a void inside the material. The generation of a thorough filament starts from the point of highest laser intensity inside the glass and builds up along the beam trajectory in the direction of laser optics.…”

Thermal conductance between water and nm-thick WS2: extremely localized probing using nanosecond energy transport state-resolved Raman

“…Thermal transport across solid-liquid interface is a topic of ongoing research due to its various applications in micro/nanoscale thermal transport, such as evaporation cooling and energy conversion, [1][2][3][4][5] thermal management, [6][7][8] ultrafast flow delivery, 9 cancer treatment, 10 solar thermal heating, 11 and nanofluids. 12,13 Continuum based interface thermal resistance (ITR) models describe this resistance as an irruption on the phonon propagation in crystalline lattice.…”