Blue, green, red fiber lasers based on Pr/Yb fluoride fibers

We report on ZBLAN fiber based praseodymium-ytterbium upconversion fiber lasers operating in the blue, green and red spectral region. We discuss advantages of the fiber laser and the operation of the upconversion lasers is described in detail. A red fiber laser running without external mirrors is presented, too. We show an unique experiment where laser parameters for many different lengths of the fiber are studied.