Active filtering of the amplitude noise of a mode-locked fiber laser

Summary form only given. Many applications today require an ultrastable optical clock such as multigigabit digital communications, analog communications, and radar. There has been a lot of recent work to reduce the timing and amplitude variation in modelocked fiber lasers to provide a suitable optical clock. Previously we have presented the reduction of phase noise (timing jitter) to below 10 fs for a source operating at 10 GHz, integrating the noise from 100 Hz to 1 MHz. We summarize initial work on reducing the amplitude fluctuations of the laser and find that not only can active filtering reduce the fluctuations by as much as 25 dB within the bandwidth of the active filter, but provides insight into the measurement of the ultralow phase noise measurements as well.