We report the delivery of high-energy nanosecond pulses (∼65 ns pulse width) from a high-repetition-rate (up to 100 kHz) Q-switched Nd:YAG laser through the fundamental mode of a hollow-core photonic crystal fiber (HC-PCF) at 1064 nm. The guided mode in the HC-PCF has a low overlap with the glass, allowing delivery of pulses with energies above those attainable with other fibers. Energies greater than 0.5 mJ were delivered in a single spatial mode through the hollow-core fiber, providing the pulse energy and high beam quality required for micromachining of metals. Practical micromachining of a metal sheet by fiber delivery has been demonstrated.
© 2005 Optical Society of America
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.2430) Fiber optics and optical communications : Fibers, single-mode
(350.3390) Other areas of optics : Laser materials processing
Jonathan D. Shephard, Francois Couny, Phillip St. J. Russell, Julian D. C. Jones, Jonathan C. Knight, and Duncan P. Hand, "Improved hollow-core photonic crystal fiber design for delivery of nanosecond pulses in laser micromachining applications," Appl. Opt. 44, 4582-4588 (2005)