Once mode-locked, repetition rates of just beyond 1 GHz were demonstrated with this design however the laser output was relatively low power. In the first, the fiber coupling was achieved through free space optics and the saturable absorbing mirror was also imaged through lenses. The next two systems are variations on a linear cavity fiber laser design. At the time, this was the highest fundamental repetition rate to be reported for a fiber cavity in a ring configuration. The first systems took advantage of a highly doped erbium fiber in a sigma cavity configuration to generate 100 fs pulses at up to a 300 MHz repetition rate through polarization additive pulse mode-locking.

This thesis describes the design, fabrication, and characterization of three different iterations of mode-locked laser sources utilizing erbium doped fibers and semiconductor saturable absorbing mirrors to form pulse trains in the 1550 nm wavelength band.

Experiments and applications like these put demanding requirements on the source laser oscillator such as operating near 1550 nm in wavelength, multi-gigahertz repetition rates, sub 100 femtosecond pulse widths, and sub 10 femtosecond timing jitters. Femtosecond fiber lasers have become an important enabling technology for advances in many areas including: frequency combs, precise timing distribution, optical arbitrary waveform generation, and high bit rate sampling for analog to digital conversion.

Nm to fs converter