Abstract

Multi-dimensional femtosecond Mid-IR spectroscopy has a well-known potential but its proliferation is held back by the absence of simple and reliable sources of tunable sub-100-fs Mid-IR pulses with microjoule energies. This work reports on the advantages of four-wave-mixing (FWM) parametric amplification in a waveguide filled with noble gas as a straightforward flexible alternative to crystal-based OPAs. Because of the low gas dispersion and waveguide confinement, a FWM OPA can compete with OPAs based on a lower, 2^nd order nonlinearity; has no spectral restrictions imposed by crystal absorption; and does not require multiple frequency-conversion cascades. Gas-filled hollow waveguides is a staple platform in ultrafast optical science [1]. Self-phase modulation (SPM) in a hollow waveguide, pioneered by Nisoli et al. [2], has been recently used to synthesize sub-cycle field waveforms in the visible and UV ranges [3]. Optical parametric amplification (OPA) in a gas-filled fiber, on the other hand, enables efficient short-pulse generation in the mid-infrared [4].

© 2015 IEEE