Stretched pulse Yb^3+:silica fiber laser

We report what we believe to be the first results on short-pulse generation in Yb(3+) :silica fiber. By applying the stretched pulse technique in a unidirectional, polarization-switch Yb(3+) fiber laser incorporating a prism-based dispersive delay line, we obtain self-start mode locking and 100-pJ pulses that can be compressed to give clean chirp-free <100-fs pulses. We believe such sources to have great potential for use not only in all-solid-state, high-power femtosecond pulse systems based on Yb(3+) :silica glass but also as seeds for conventional Nd(3+) :glass amplifier chains.