Practical low-noise stretched-pulse Yb3+-doped fiber laser

We report on the development of what we consider to be a practical and highly stable stretched-pulse laser based on Yb3+-doped silica fiber. The Fabry-Perot cavity uses nonlinear polarization rotation as the mode-locking mechanism, and a semiconductor saturable-absorber mirror to ensure robust self-starting and incorporates a diffraction grating pair to compensate for the normal dispersion of the fiber. Use of a single-mode grating-stabilized telecommunications-qualified pump laser diode ensures reliable, low-noise operation (similar to0.05% amplitude fluctuations at 10-Hz measurement bandwidth). The laser generates high-quality, 60-pJ pulses of <110-fs duration at a repetition rate of similar to54 MHz (3-mW average power). (C) 2002 Optical Society of America.