Exploring the limits of semiconductor-laser-based optical frequency combs

Recent Advances in the Photonic Integration of Mode-Locked Laser Diodes

“…Very similar as in continuous wave lasers, the noise can be reduced by making use of extended cavity solutions. This can be achieved by adding a free space or fiber section to the laser cavity [9]. This idea is at the core of extended InP and III/V-on-silicon lasers and will be discussed in the following sections.…”

“…Such that one could approach the performance of free space and fibre-based extended cavity systems (e.g. [9]). The remainder of the letter will discuss these two approaches.…”

Towards On-Chip Self-Referenced Frequency-Comb Sources Based on Semiconductor Mode-Locked Lasers

“…These include the gain current, operating temperature, reverse voltage of the saturable absorber and the current in an integrated phase-shifter. Furthermore, these parameters simultaneously affect the CEO and the repetition rate [34]. It is preferential to choose a free parameter and operating conditions that affect mostly the CEO, while keeping the repetition rate fixed.…”

“…The comparison presented here is by no means a thorough review of semiconductor MLLs and the reader is directed to references [34,56,57]. Table 2 collects performance of representative lasers.…”

“…In other words, the linewidth of individual comb teeth increases as we move away from fr [52]. In the case of active/hybrid MLLs, the fixed point is located near the carrier frequency, while in passive MLLs it is close to the zero frequency [34]. In CEO detection experiments, the comb teeth that are beat against one another (after frequency multiplication) are on the extremes of the spectrum.…”