Observation of quantum-limited timing jitter in an active, harmonically mode-locked fiber laser.

We report on the observation of quantum-limited timing jitter in a harmonically mode-locked soliton fiber laser with an ultralow-noise local oscillator. The effects of amplitude and phase modulation on the spectrum are described and compared with theory.

Self-stabilized passive, harmonically mode-locked stretched-pulse erbium fiber ring laser.

We have studied a passive, harmonically mode-locked stretched-pulse erbium fiber ring laser with net positive dispersion that is self-stabilized by gain depletion and electrostriction. Periodic pulses with supermode suppression of >75 dB and picosecond jitter are achieved. The pulses are compressible to 125 fs by external chirp compensation. The repetition rate is 220 MHz, and the average power is as high as 80 mW.

Timing restoration dynamics in an actively mode-locked fiber ring laser.

Using electronic phase detection, we study the dynamics that govern pulse retiming in an actively mode-locked fiber laser. We compare the dynamics for amplitude and for phase modulation and identify the characteristic time constants for each case. The retiming dynamics for amplitude modulation are revealed as a first-order exponential decay, whereas for phase modulation the dynamics are those of a damped harmonic oscillator. We show that the measured time constants agree with predictions given by the soliton perturbation theory.

Photon statistics of amplified spontaneous emission noise in a 10-Gbit/s optically preamplified direct-detection receiver.

We verify experimentally, over a dynamic range of 55 dB in the probability distribution, that the amplified spontaneous emission noise of the 0's from an optically preamplified receiver is degenerate Bose-Einstein distributed. Using the noise parameters extracted from the experiment, we are able to predict the sensitivity of a 10-Gbit/s direct-detection receiver.