Laser frequency combs are light sources that produce evenly spaced, sharp lines across the spectrum, resembling the teeth of a comb. They serve as precise rulers for measuring time and frequency, and have become essential tools in applications such as lidar, high-speed optical communications, and space navigation. Traditional frequency combs rely on large, lab-based lasers. However, recent advancements have led to the development of chip-scale soliton microcombs, which generate ultrashort pulses of light within microresonators.
One of the key challenges for soliton microcombs is timing jitter, which refers to tiny fluctuations in the timing of their light pulses. These fluctuations, caused by environmental noise or internal instabilities, can degrade the precision and reliability of systems that rely on exact timing. For example, in lidar, jitter can cause uncertainty in distance measurements, and in high-speed data transmission, it can introduce signal distortion and reduce data integrity.
As reported in Advanced Photonics Nexus, an international research team has addressed this problem by developing a new platform based on dispersion-managed (DM) silicon nitride (Si3N4) microresonators operating at an 89 GHz repetition rate.