Watt-level, Duration-tunable Picosecond Source at 560 nm by Second-harmonic Generation of a Raman Fiber Laser

High peak-power sources at 560 nm with excellent beam quality are in high demand for a diverse range of applications, including fluorescence microscopy, biochemical analysis and semiconductor characterization [1]. Direct generation of this strategic wavelength is possible with gain-switched laser diodes, but these suffer from limited average power and poor beam quality at fixed pulse durations. Nonlinear conversion techniques such as fiber-based supercontinuum sources or bulk parametric conversion of ultrafast oscillators typically produce limited pulse energies. In this contribution, we present a novel fiber architecture for generating narrow-linewidth, duration-tunable picosecond radiation at 1120 nm. Second-harmonic generation (SHG) in a bulk periodically-poled (PP) crystal of this source results in > 1 W of 560 nm with a conversion efficiency of > 45%.