Abstract

Hollow-core photonic crystal fibers (HC-PCF) offer a combination of long effective interaction length and small mode areas which has resulted in several major breakthroughs in low-power nonlinear optics (see e.g. [1-3]). Recently, it was shown numerically that such fibers offer unique properties in terms of efficiency and low threshold for high harmonic generation (HHG) [4]. In addition to the substantial decrease in pump threshold, the efficiency is expected to be significantly enhanced by guiding and improved phase-matching using optimized dispersion engineering in PCFs. Traditionally, HHG has been carried out using complex femtosecond laser amplifier systems operating at low repetition rates in the kHz-regime with pulse energies of more than 100 μJ and an unguided interaction using a gas-jet target. In recent years, however, there has been considerable interest in the development of HHG sources operating in the VUV/XUV spectral region with multi-megahertz repetition rates, which can substantially increase the signal-to-noise ratio for numerous applications.

© 2009 IEEE