An investigation of long pulsed laser induced damage in sapphire

Abstract The formation of keyhole and transverse section of a laser-cut kerf with slight stripe undulations by a 1064 nm ms pulse laser on (0 0 0 1) sapphire was investigated. The morphologies of keyhole and transverse section surfaces were evaluated by SEM, and the composition of transverse section of laser-cut kerf was evaluated by EDS, XRD and XPS. The time scale for onset of vaporization and the keyhole depth with different laser pulse energies were calculated. The result suggests that the depth of keyhole is approximately directly proportional to laser pulse energy. On sapphire transverse section surface, the element ratio of Al to O deviates from the stoichiometry of sapphire, perhaps due to the oxygen removal from surface.

[1]  S. Ma,et al.  Sapphire (112-bar0) surface: Structure and laser-induced desorption of aluminum. , 1992 .

[2]  A. Tam,et al.  Mechanism of picosecond ultraviolet laser sputtering of sapphire at 266 nm , 1990 .

[3]  Jyh-Chen Chen,et al.  Numerical computation of sapphire crystal growth using heat exchanger method , 2001 .

[4]  S. Ko,et al.  Mechanism of keyhole formation and stability in stationary laser welding , 2002 .

[5]  Juergen Reif,et al.  Laser-induced ion emission from dielectrics , 2000 .

[6]  L. Schlessinger,et al.  Inverse-bremsstrahlung absorption rate in an intense laser field , 1979 .

[7]  David Ashkenasi,et al.  Laser processing of sapphire with picosecond and sub-picosecond pulses , 1997 .

[8]  Ernst-Wolfgang Kreutz,et al.  Laser-induced plasma formation during pulsed laser deposition , 1993 .

[9]  Y. Yao,et al.  Time scale effects in laser material removal: a review , 2005 .

[10]  U. Dilthey,et al.  Kinetic description of keyhole plasma in laser welding , 2000 .

[11]  D. Zeze,et al.  AES and EELS study of alumina model catalyst supports , 1997 .

[12]  R. Russo,et al.  Numerical modeling of pulsed laser evaporation of aluminum targets , 1998 .

[13]  A. Kar,et al.  Two‐dimensional model for material damage due to melting and vaporization during laser irradiation , 1990 .

[14]  Gerard Mourou,et al.  Optics at critical intensity: applications to nanomorphing. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[15]  Jae-Won Park,et al.  X-ray photoelectron spectroscopy of uv laser irradiated sapphire and alumina , 1994 .

[16]  M. Kohyama,et al.  Electronic Structure and Chemical Reactions at Metal–Alumina and Metal–Aluminum Nitride Interfaces , 1991 .

[17]  W. Steen.  Laser Material Processing , 1991 .

[18]  D. Price,et al.  Structure of Liquid Aluminum Oxide , 1997 .

[19]  Lv. Shanjin,et al.  An investigation of pulsed laser cutting of titanium alloy sheet , 2006 .

[20]  E. Campbell,et al.  A general continuum approach to describe fast electronic transport in pulsed laser irradiated materials: The problem of Coulomb explosion , 2005 .

[21]  Siyuan Zhang,et al.  Lattice energy estimation for inorganic ionic crystals. , 2003, Inorganic chemistry.

[22]  W. P. Latham,et al.  Two-dimensional model for melting and vaporization during optical trepanning , 2005 .

[23]  Alexei A. Maradudin,et al.  Theory of electron-avalanche breakdown in solids , 1980 .

[24]  J. Rothenberg,et al.  Laser produced plasma in crystalline α‐Al2O3 and aluminum metal , 1984 .