Abstract

The delivery of nanosecond laser pulses through flexible tapered fibers to launch hypervelocity flyer plates has been achieved and investigated. The Nd:YAG laser was used to launch Al and composite sandwiched (200 nm Al/4.5 μm Al₂O₃/800 nm Al) flyers from optical substrates, coated with thin layers to absorb the laser energy, confine the plasma, and construct the flyers. In order to improve power handling capacity of the laser-driven flyer system, the tapered fibers were employed. Laser-induced damage experiments on ten tapered fibers with different lengths and taper ratios were carried out. It is also found the maximal transmission pulse energy with 15ns pulse width at 1064 nm wavelength of the tapered fiber is 2-3 times higher than that of the traditional one. With delivered pulse energy through tapered fibers of 30-50 mJ, velocities of 1-1.7 km/s were obtained and the flyers were 5.5 μm thick with a diameter of circa 1 mm.

© 2011 Optical Society of America