Energetic mid-IR femtosecond pulse generation by self-defocusing soliton-induced dispersive waves in a bulk quadratic nonlinear crystal

Abstract

Generating energetic femtosecond mid-IR pulses is crucial for ultrafast spectroscopy, and currently relies on parametric processes that, while efficient, are also complex. Here we experimentally show a simple alternative that uses a single pump wavelength without any pump synchronization and without critical phase-matching requirements. Pumping a bulk quadratic nonlinear crystal (unpoled LiNbO${}_3$ cut for noncritical phase-mismatched interaction) with sub-mJ near-IR 50-fs pulses, tunable and broadband ($\sim 1,000$ cm${}^{-1}$) mid-IR pulses around $3.0\mu \mathrm{m}$ are generated with excellent spatio-temporal pulse quality, having up to 10.5 $\mu$J energy (6.3% conversion). The mid-IR pulses are dispersive waves phase-matched to near-IR self-defocusing solitons created by the induced self-defocusing cascaded nonlinearity. This process is filament-free and the input pulse energy can therefore be scaled arbitrarily by using large-aperture crystals. The technique can readily be implemented with other crystals and laser wavelengths, and can therefore potentially replace current ultrafast frequency-conversion processes to the mid-IR.

submitted

References in corpus (4)

• Nonlocal explanation of stationary and nonstationary regimes in cascaded soliton pulse compression
• Limits to compression with cascaded quadratic soliton compressors
• Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities
• Efficient supercontinuum generation in quadratic nonlinear waveguides without quasi-phase matching

Cited by in corpus (2)

• Photoionization-induced emission of tunable few-cycle mid-IR dispersive waves in gas-filled hollow-core photonic crystal fiber
• Peregrine solitons and resonant radiation in cubic and quadratic media