Yb fiber based laser source for tunable, narrow bandwidth picosecond pulses in the visible

We present a simple Yb fiber pumped source for narrow bandwidth picosecond pulses which are tunable in the visible spectral region. This emission is obtained by frequency doubling of a soliton generated in a photonic crystal fiber. The system is attractive for different types of nonlinear optical microscopy and can easily be adapted to meet different experimental prerequisites. As an example, we demonstrate coherent anti-Stokes Raman scattering microscopy using the laser source described.