Phys.org February 23, 2022
A team of researchers in the US (NIST, University of Maryland) has produced a microcomb using two lasers, each generating a different frequency of light, instead of just one. They found that through a complex series of interactions with the soliton light circulating in the microring resonator, the second laser induced two new sets of teeth, or evenly spaced frequencies, that are replicas of the original set of teeth but shifted to higher and lower frequencies. The lower frequency set lies in the infrared part of the spectrum, while the other is at much high frequencies, close to visible light. The comb also retains its original teeth, at near-infrared frequencies. The extended range of the microcomb enables a host of applications at different frequencies. In addition, the team discovered that by varying the frequency of the second laser, the new sets of teeth could be easily shifted to higher or lower frequencies independent of the shape or composition of the microring resonator. This makes the system extremely versatile. The expanded range of the microcomb could lead to better sensors of greenhouse gases and may also improve global navigation systems…read more. Open Access TECHNICAL ARTICLEÂ
Relative phase noise between the primary and synthesis portions. Credit: Nature Communications volume 12, Article number: 7275 (2021)Â