Multiple-octave spanning mid-IR supercontinuum generation in bulk quadratic nonlinear crystals

Abstract

Bright and broadband coherent mid-IR radiation is important for exciting and probing molecular vibrations. Using cascaded nonlinearities in conventional quadratic nonlinear crystal like lithium niobate, self-defocusing near-IR solitons have been demonstrated that led to very broadband supercontinuum generation in the visible, near-IR and short-wavelength mid-IR. Here we conduct an experiment where a mid-IR crystal pumped in the mid-IR gives multiple-octave spanning supercontinua. The crystal is cut for noncritical interaction, so the three-wave mixing of a single mid-IR femtosecond pump source leads to highly phase-mismatched second-harmonic generation. This self-acting cascaded process leads to the formation of a self-defocusing soliton at the mid-IR pump wavelength and after the self-compression point multiple octave-spanning supercontinua are observed (covering 1.6-$7.0\mu$m). The results were recorded in a commercially available crystal LiInS${}_2$ pumped in the 3-$4\mu$m range, but other mid-IR crystals can readily be used as well.

submitted to APL Photonics

References in corpus (4)

• Nonlocal explanation of stationary and nonstationary regimes in cascaded soliton pulse compression
• Experimental observation of long-wavelength dispersive wave generation induced by self-defocusing nonlinearity in BBO crystal
• Energetic mid-IR femtosecond pulse generation by self-defocusing soliton-induced dispersive waves in a bulk quadratic nonlinear crystal
• The Nonlinear Analytical Envelope Equation in quadratic nonlinear crystals

Cited by in corpus (6)

• Swept-wavelength mid-infrared fiber laser for real-time ammonia gas sensing
• Ultra-low-noise supercontinuum generation with a flat near-zero normal dispersion fiber
• Parametrically tunable soliton-induced resonant radiation by three-wave mixing
• Noise in supercontinuum generated using PM and non-PM tellurite glass all-normal dispersion fibers
• Multiple soliton compression stages from competing plasma nonlinearities in mid-IR gas-filled hollow-core fibers
• Peregrine solitons and resonant radiation in cubic and quadratic media