Yb-Fiber-Amplification of Harmonically Mode-Locked Semiconductor-Laser-Pulses

There has been recent interest in the development of Yb-doped fiber master oscillator power amplifier (MOPA) systems which utilize a short pulse semiconductor laser as the seed source [1]. Semiconductor lasers that are mode-locked are well suited to seed fiber-MOPAs since they are capable of directly generating short picosecond pulses at up to gigahertz repetition rates with low timing jitter. Additionally, mode-locked diode sources offer good flexibility of pulse parameters such as the duration, repetition rate, and wavelength. However, there has been little reported on the development of mode-locked semiconductor seed-sources for Yb-doped fiber amplifiers (YDFAs). We present results on a picosecond-pulse diode laser that provides 60 nm of wavelength tuning and can be passively mode-locked at up to the eighth harmonic of the cavity round-trip frequency. Amplification of the diode oscillator in a single-stage YDFA (CorActive fiber) when mode-locked at different harmonics is also described.