title: Enhanced four-wave mixing in a hollow-core photonic-crystal fiber.
abstract: Hollow-core photonic-crystal fibers are shown to substantially enhance four-wave mixing (FWM) of laser pulses in a gas filling the fiber core. Picosecond pulses of Nd:YAG fundamental radiation and its second harmonic are used to generate a signal at the frequency of the third harmonic by the FWM process 3omega = 2omega + 2omega - omega. The efficiency achieved for this process in a 9-cm-long, 13-microm-hollow-core-diameter photonic-crystal fiber, designed to simultaneously transmit a two-color pump and the FWM signal, is shown to be approximately 800 times higher than the maximum FWM efficiency attainable with the same laser pulses in the tight-focusing regime.
authors.affiliation: Department of Physics, International Laser Center, M. V. Lomonosov Moscow State University, 119899 Moscow, Russia.
authors.forename: S O
authors.initials: SO
authors.lastname: Konorov
authors.forename: A B
authors.initials: AB
authors.lastname: Fedotov
authors.forename: A M
authors.initials: AM
authors.lastname: Zheltikov