Transmission Welding of Glass by Femtosecond Laser: Mechanism and Fracture Strength

Femtosecond laser pulses were focused on the interface of two glass specimens. Proper use of optical and laser processing parameters enables transmission welding. The morphology of the weld cross section was studied using differential interference contrast optical microscopy. In addition, a numerical model was developed to predict the absorption volumes of femtosecond laser pulses inside a transparent material. The model takes into account the temporal and spatial characteristics and propagation properties of the laser beam, and the transmission welding widths were subsequently compared with the absorption widths predicted by the model. The model can lead to the achievement of a desirable weld shape through understanding the effects of laser pulse energy and numerical aperture on the shape of the absorption volume. The changes in mechanical properties of the weld seams were studied through spatially resolved nanoindentation, and indentation fracture analysis was used to investigate the strength of the weld seams.

[1]  F. Yoshino,et al.  Fusion Welding of Glass Using Femtosecond Laser Pulses with High-repetition Rates , 2007 .

[2]  J. Nishii,et al.  Space-selective laser joining of dissimilar transparent materials using femtosecond laser pulses , 2006 .

[3]  K. Sokolowski-Tinten,et al.  Timescales in the response of materials to femtosecond laser excitation , 2004 .

[4]  G. Irwin.  Crack-Extension Force for a Part-Through Crack in a Plate , 1962 .

[5]  Kazuyoshi Itoh,et al.  Joining of transparent materials by femtosecond laser pulses , 2007, SPIE LASE.

[6]  J. Kitchener,et al.  Direct Measurement of Long-Range van der Waals Forces , 1956, Nature.

[7]  A. Bourgeade,et al.  Model and numerical simulations of the propagation and absorption of a short laser pulse in a transparent dielectric material: Blast-wave launch and cavity formation , 2007 .

[8]  Michael Schmidt,et al.  Novel fusion welding technology of glass using ultrashort pulse lasers , 2008 .

[9]  J. Nishii,et al.  Welding of Transparent Materials Using Femtosecond Laser Pulses , 2005 .

[10]  Leonid V. Zhigilei,et al.  Microscopic mechanisms of laser ablation of organic solids in the thermal and stress confinement irradiation regimes , 2000 .

[11]  C. Schaffer,et al.  Three-dimensional micromachining inside transparent materials using femtosecond laser pulses: New applications , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[12]  Klaus Sokolowski-Tinten,et al.  Transient States of Matter during Short Pulse Laser Ablation , 1998 .

[13]  A. Miotello,et al.  Laser-induced phase explosion: new physical problems when a condensed phase approaches the thermodynamic critical temperature , 1999 .

[14]  W. Webb,et al.  Nonlinear magic: multiphoton microscopy in the biosciences , 2003, Nature Biotechnology.

[15]  J. Gottmann,et al.  Local Melting of Glass Material and Its Application to Direct Fusion Welding by Ps-laser Pulses , 2007 .

[16]  Hongliang Wang,et al.  Characterization of Morphology and Mechanical Properties of Glass Interior Irradiated by Femtosecond Laser , 2010 .

[17]  A. Varshneya.  Fundamentals of Inorganic Glasses , 1993 .

[18]  N. Soga.  Elastic moduli and fracture toughness of glass , 1985 .

[19]  Yves Bellouard,et al.  Nanoindentation and birefringence measurements on fused silica specimen exposed to low-energy femtosecond pulses. , 2006, Optics express.

[20]  A. Horn,et al.  Investigations on ultrafast welding of glass–glass and glass–silicon , 2008 .

[21]  Zhu Cong-Shan,et al.  Thermal Stress-Induced Birefringence in Borate Glass Irradiated by Femtosecond Laser Pulses , 2005 .

[22]  Hiroshi Tada,et al.  The stress analysis of cracks handbook , 2000 .

[23]  M. Deighton.  Fracture of Brittle Solids , 1976 .

[24]  K. Itoh,et al.  Laser micro-welding of transparent materials by a localized heat accumulation effect using a femtosecond fiber laser at 1558 nm. , 2006, Optics express.

[25]  Saulius Juodkazis,et al.  Laser-Matter Interaction in Transparent Materials: Confined Micro-explosion and Jet Formation , 2010 .

[26]  P. Corkum,et al.  Stress in femtosecond-laser-written waveguides in fused silica. , 2004, Optics letters.

[27]  Saulius Juodkazis,et al.  Laser-matter interaction in the bulk of a transparent solid: confined microexplosion and void formation , 2006 .

[28]  J. J. Mecholsky,et al.  The application of fractal and quantum geometry to brittle fracture , 1999 .

[29]  W. Kern.  The Evolution of Silicon Wafer Cleaning Technology , 1990 .

[30]  Eric Mazur,et al.  Morphology of femtosecond laser-induced structural changes in bulk transparent materials , 2004 .

[31]  Denise M. Krol,et al.  Femtosecond laser modification of glass , 2008 .

[32]  D. Rowcliffe,et al.  Nanoindentation Method for Measuring Residual Stress in Brittle Materials , 2003 .

[33]  P. Sharma.  Mechanics of materials. , 2010, Technology and health care : official journal of the European Society for Engineering and Medicine.

[34]  Measurements, transformations, and high-temperature fracture , 1983 .