Tunable femtosecond near-IR source by pumping an OPA directly with a 90 MHz Yb:fiber source Mundry, J. Lohrenz, J. Betz, M. Infrared and far-infrared lasers Ultrafast lasers Nonlinear optics parametric processes Parametric oscillators and amplifiers Femtosecond pulses Fiber lasers Fused silica Laser systems Photonic crystal fibers Pulse propagation Up to 400 mW of near-IR (1370-1500 nm) femtosecond pulses are generated from an optical parametric amplifier directly driven by a Yb:fiber oscillator delivering 100\&\#x00A0;fs pulses at 1036 nm. The process is seeded by a stable supercontinuum obtained from a photonic crystal fiber. We use a single pass through a 3 mm, magnesium oxide-doped, periodically poled LiNbO3 downconversion crystal to produce a near-IR pulse train with a remarkable power stability of 1.4 % (RMS) during one hour. Tuning is achieved by the temperature and the poling period of the nonlinear crystal. OSA 2017 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/6543 Mundry J, Lohrenz J, Betz M. Tunable femtosecond near-IR source by pumping an OPA directly with a 90 MHz Yb:fiber source. <i>Applied Optics</i>. 2017;56(11):3104-3108. doi:<a href="https://doi.org/10.1364/AO.56.003104">10.1364/AO.56.003104</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1364/AO.56.003104 info:eu-repo/semantics/closedAccess