Pulsed Ultralong Ultrafast Ring Fiber Oscillators.

In this talk we will review the state of the art on the topic of ultralong passively mode-locked femtosecond pulse fiber oscillators. This new fiber laser architecture relies on the use of polarization-insensitive InN-based semiconductor saturable absorber mirrors (SESAMs) and the careful management of nonlinearities in multi-kilometric fibre rings with Erbium Doped Fiber Amplifier (EDFA)-based amplification. These new sources are capable of supporting the stable generation of soliton-like pulses with durations below 200 fs, overcoming previously assumed limitations to pulse duration in ultralong lasers, and reach ultra-low repetition rates as low as a few tens of kHz with the assistance of Raman amplification. The unique characteristics of this new family of ultrafast fiber oscillators make them suitable for a broad range of potential applications.