Timing jitter in ultralong ultrafast ring fiber lasers

The recent introduction of a novel class of ultralong passively mode-locked femtosecond pulse fiber oscillators, offering high-power pulses with ultra-low repetition rates of the order of kHz while relying on low-cost standard telecommunication components, paves the way for several interesting applications, from materials processing to metrology and environmental sensing. Some of these applications, such as those based on the generation of optical frequency combs, are particularly dependent on phase noise characteristics, and thus it becomes relevant to study its dependence of system design parameters. Here we present a simple method for the estimation of timing jitter and phase noise in ultralong ultrashort laser setups, demonstrating peak-to-peak jitter in the range of the tens of fs.