A research team at the Institute of Physics of the Chinese Academy of Sciences in Beijing has used self-guided plasma channels created in air by a femtosecond laser to propel a 1.32-g paper airplane along an air-cushion track. The work, which the team reported in the Dec. 26 issue of Optics Express, suggests that continuous focusing of the laser is not necessary in off-board propulsion schemes, which are being considered as a means of maximizing payloads in tiny, ultralight aircraft.

In the experiments, the investigators used a home-built Ti:sapphire chirped-pulse amplification system operating at a repetition rate of 10 Hz to generate 30-fs pulses of 800-nm radiation with energies of up to 640 mJ. The optical Kerr effect in air results in self-focusing of the pulse train, which photoionizes the air to produce the meters-long plasma channels, and a detonation wave that can propel targets in a length of the channels.