title: Use of hollow core fibers, fiber lasers, and photonic crystal fibers for spark delivery and laser ignition in gases.
abstract: The fiber-optic delivery of sparks in gases is challenging as the output beam must be refocused to high intensity (approximately 200 GW/cm(2) for nanosecond pulses). Analysis suggests the use of coated hollow core fibers, fiber lasers, and photonic crystal fibers (PCFs). We study the effects of launch conditions and bending for 2 m long coated hollow fibers and find an optimum launch f# of approximately 55 allowing spark formation with approximately 98% reliability for bends up to a radius of curvature of 1.5 m in atmospheric pressure air. Spark formation using the output of a pulsed fiber laser is described, and delivery of 0.55 mJ pulses through PCFs is shown.
authors.affiliation: Engines and Energy Conversion Laboratory, Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80524, USA.
authors.forename: Sachin
authors.initials: S
authors.lastname: Joshi
authors.forename: Azer P
authors.initials: AP
authors.lastname: Yalin
authors.forename: Almantas
authors.initials: A
authors.lastname: Galvanauskas