Simultaneous generation of spectrally distinct third harmonics in a photonic crystal fiber

Abstract

By coupling femtosecond pulses at lambda - 1.55mum in a short length (Z - 95 cm) of photonic crystal fiber, we observe the simultaneous generation of two visible radiation components. Frequency-resolved optical gating experiments combined with analysis and modal simulations suggest that the mechanism for their generation is third-harmonic conversion of the fundamental pulse and its split Raman self-shifted component.

UV generation in a pure-silica holey fiber

“…Despite the wide interest in supercontinuum research, there have been few previous reports of the supercontinuum in higher order spatial modes [13,21,22]. Due to the large index difference between core and cladding modes of small-core high-air-fill-fraction holey fibers, the effective index of the fundamental mode, which is mostly confined within the core, is substantially greater than for higher order modes, which extend into the holey cladding.…”

Progress in Continuous-Wave Supercontinuum Generation

“…The green spectral components located around 550 nm are clearly generated in higher-order modes. This part of the spectrum was not expected from our design and is probably due to a phase-matching condition satisfied with higher-order modes Efimov et al (2003); Omenetto et al (2001). The far-field image recorded at 700 nm shows that the red spectral components are generated in a fundamental mode.…”

High-Energy Four-Wave Mixing, with Large-Mode-Area Higher-Order Modes in Optical Fibres

“…This is based on the realization that ZDW in higher order modes (HOM) of fibers scales with mode order in analogy to ZDW scaling with mode area in PCFs 3 . Thus phase matching for the nonlinear process is achieved by choosing the interacting modes accordingly 4,5 . This, combined with the experimentally-proven fact that HOMs are more stable than the fundamental mode of suitably designed large A eff fibers 6 , enables the development of fibers that can yield wavelength conversions at dramatically higher power levels.…”