  Over the last decade advances in high temperature superconducting (HTS)
materials have generated a renewed optimism in the use of this technology in
future high-power applications including motors, generators, and power
transmission. The most promising superconducting material, YBa2Cu3O6+x (YBCO),
has demonstrated current density capacity as high as 106 A/cm2 and is typically
deposited epitaxially as a thin film on a buffered metallic substrate. The
coated conductor architecture Ag/YBCO/Buffer/Ni-based substrate, as does other
heteromaterials, introduces unique challenges to the laser micromachining
process. In the present study, optimization of the laser micromachining process
for machining grooves extending through the YBCO into the buffer layer is
considered. A frequency tripled diode-pumped solid-state Nd:YVO4 laser at 355
nm is used in conjunction with both fixed and scanning optical systems. The
dependence of cut quality, dimension, and local damage to the YBCO layer on the
laser processing parameters including focal spot size, pulse overlap, and
fluence will be discussed. Preliminary experimental results indicate that laser
micromachining may be used as a reliable process for patterning of
superconducting tapes.
