A comparison between an in-field and an in-laboratory 50 km ultralong Erbium fiber laser

We present a comparison between an in-held and an in-laboratory 50 km ultralong erbium-doped fiber lasers operating in active mode-locking regime. The results show better performance of the in-laboratory laser with pulses from 36.1 to 97.3 ps with repetition rate from 1 to 10 GHz.