Ultrashort light pulses in hollow waveguides

Ultrafast-optics applications of nonlinear-optical processes in gas-filled hollow fibers are briefly reviewed. The main physical processes behind the use of hollow fibers for efficient generation of unprecedentedly short light pulses, enhanced short-wavelength generation, and improvement of the sensitivity of nonlinear-optical gas-phase analysis are considered. These processes include self- and cross-phase modulation, coherent four-wave mixing, high-order harmonic generation, and stimulated Raman scattering. The methods to generate extremely short pulses, including few-cycle field waveforms, and to control such pulses are discussed.