On type I cascaded quadratic soliton compression in lithium niobate: Compressing femtosecond pulses from high-power fiber lasers

Abstract

The output pulses of a commercial high-power femtosecond fiber laser or amplifier are typically around 300-500 fs with a wavelength around 1030 nm and 10s of $\mu$J pulse energy. Here we present a numerical study of cascaded quadratic soliton compression of such pulses in LiNbO${}_3$ using a type I phase matching configuration. We find that because of competing cubic material nonlinearities compression can only occur in the nonstationary regime, where group-velocity mismatch induced Raman-like nonlocal effects prevent compression to below 100 fs. However, the strong group velocity dispersion implies that the pulses can achieve moderate compression to sub-130 fs duration in available crystal lengths. Most of the pulse energy is conserved because the compression is moderate. The effects of diffraction and spatial walk-off is addressed, and in particular the latter could become an issue when compressing in such long crystals (around 10 cm long). We finally show that the second harmonic contains a short pulse locked to the pump and a long multi-ps red-shifted detrimental component. The latter is caused by the nonlocal effects in the nonstationary regime, but because it is strongly red-shifted to a position that can be predicted, we show that it can be removed using a bandpass filter, leaving a sub-100 fs visible component at $\lambda =515$ nm with excellent pulse quality.

14 pages, 10 figures, 1 table, submitted to PRA

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
• Designing microstructured polymer optical fibers for cascaded quadratic soliton compression of femtosecond pulses

Cited by in corpus (9)

• Ultrafast and octave-spanning optical nonlinearities from strongly phase-mismatched cascaded interactions
• The anisotropic Kerr nonlinear refractive index of the beta-barium borate (β-BaB2O4) nonlinear crystal
• Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle energetic near- to mid-IR pulses
• Soliton-induced nonlocal resonances observed through high-intensity tunable spectrally compressed second-harmonic peaks
• Nonlinear Wave Equation in Frequency Domain: Accurate Modeling of Ultrafast Interaction in Anisotropic Nonlinear Media
• Review of measurements of Kerr nonlinearities in lithium niobate: the role of the delayed Raman response
• Spatio-Temporal Mode-locking in Quadratic Nonlinear Media
• Solitons near avoided mode crossing in ${\chi }^{(2)}$ nanowaveguides
• Solid-state Mamyshev oscillator