title: Use of hollow-core fibers to deliver nanosecond Nd:YAG laser pulses to form sparks in gases.
abstract: We report what is to our knowledge the first delivery of nanosecond laser pulses through flexible fibers to produce optical sparks in atmospheric-pressure gases. Our work employs a Nd:YAG laser beam (1.064 microm) delivered through a cyclic olefin polymer-coated silver hollow fiber. We studied the beam properties at the fiber exit as a function of the fiber launch geometry. We found that for a low-angle launch (approximately 0.01 rad half-angle), the exit beam has relatively high optical intensity (approximately 2 GW/cm2) and low light divergence (approximately 0.01 rad half-angle) and allows downstream spark formation. The effect of fiber bending on the exit beam and on the ability to make sparks is also investigated.
authors.affiliation: Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA. ayalin@engr.colostate.edu
authors.forename: A P
authors.initials: AP
authors.lastname: Yalin
authors.forename: M
authors.initials: M
authors.lastname: DeFoort
authors.forename: B
authors.initials: B
authors.lastname: Willson
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuura
authors.forename: M
authors.initials: M
authors.lastname: Miyagi