GUIDED-WAVE PHASE-MATCHING OF ULTRASHORT-PULSE LIGHT

Abstract

We review the use of hollow waveguides for frequency conversion of ultrafast laser pulses the ultraviolet and extreme ultraviolet. Phase-matching of these processes is reached through a balance of gas and waveguide dispersion. By mixing 400 nm with 800 nm light, ultrashort (8 fs) pulses are generated near 270 nm with high efficiency > 20%. Tuning of the longer-wavelength component in the mixing process allows tuning of the output from 215–308 nm. In the XUV, this guided-wave phase-matching has allowed an increase of conversion efficiency of high-order harmonic generation of 100–1000x over that obtained with a gas jet, in an experimentally-convenient geometry.