Characterization of timing jitter in a 5 GHz quantum dot passively mode-locked laser

Abstract

The timing jitter performance of a 5 GHz quantum dot passively mode-locked laser is investigated at different harmonics in the RF spectrum. The necessity of measuring the phase noise at relatively large harmonic numbers is motivated experimentally in the context of determining the corner frequency, its correlation to the RF linewidth, and the related white noise plateau level. The single-sideband phase noise with an integrated timing jitter of 211 fs (4-80 MHz) is reported. An all-microwave technique has been used to determine a pulse-to-pulse rms timing jitter of 96 fs/cycle. This low timing jitter value makes the chip-scale quantum dot mode-locked laser an attractive source for low noise applications such as optical clocking and sampling.

Delay-induced dynamics and jitter reduction of passively mode-locked semiconductor lasers subject to optical feedback

“…Compared to actively [4] and hybrid ML lasers they are simpler to fabricate and to handle. However, their major drawback is their relatively large timing jitter due to the absence of an external reference clock [5]. Since timing fluctuations degrade the performance of the laser, a great deal of efforts have been made to reduce them.…”

Impact of Self Noise on Tracking Performance of Non-Data-Aided Digital Timing Recovery

“…We have checked that the performance of the cascade of two moving average filters is within 0.07 to 0.2 decibels from the performance of the optimal post-filter (47). Also, we have simulated the performance of the detector of [11], which turns out to be virtually indistinguishable from the performance of the detector (17), (18).…”

“…For instance, a passively mode locked laser oscillator at frequency T −1 = 40 GHz is characterized by γ 2 = 4 · 10 −6 , leading to a power spectral density of phase noise at 100 kHz from the peak equal to −64 dBcarrier/Hz [18], while an active mode-locked laser oscillator, that has better quality than the passive one, has γ 2 = 10 −8 , that is −90 dBcarrier/Hz at 100 kHz from the peak of the spectral line [19]. An even better phase noise spectrum can be obtained by a system based on a VCO with natural frequency around 10 GHz locked to a reference crystal oscillator [20].…”

Wider-frequency combs generation, noise reduction, and repetition rate tuning in quantum-dot mode-locked lasers

“…Passive mode-locking is more cost-efficient and robust to implement when compared with active or hybrid mode-locking. However, frequency combs generated by passively mode-locked lasers (PMLLs) often exhibit large phase noise and jitter, which makes them ineffective in highspeed applications [4]. Therefore, noise stabilization techniques are required to improve performance of QD-PMLLs.…”