Platicon microcomb generation using laser self-injection locking
Abstract
The past decade has witnessed major advances in the development and system-level applications of photonic integrated microcombs, that are coherent, broadband optical frequency combs with repetition rates in the millimeter-wave to terahertz domain. Most of these advances are based on harnessing of dissipative Kerr solitons (DKS) in microresonators with anomalous group velocity dispersion (GVD). However, microcombs can also be generated with normal GVD using localized structures that are referred to as dark pulses, switching waves or platicons. Compared with DKS microcombs that require specific designs and fabrication techniques for dispersion engineering, platicon microcombs can be readily built using CMOS-compatible platforms such as thin-film (i.e., thickness below 300 nm) silicon nitride with normal GVD. Here, we use laser self-injection locking to demonstrate a fully integrated platicon microcomb operating at a microwave K-band repetition rate. A distributed feedback (DFB) laser edge-coupled to a Si3N4 chip is self-injection-locked to a high-Q ( > 107) microresonator with high confinement waveguides, and directly excites platicons without sophisticated active control. We demonstrate multi-platicon states and switching, perform optical feedback phase study and characterize the phase noise of the K-band platicon repetition rate and the pump laser. Laser self-injection-locked platicons could facilitate the wide adoption of microcombs as a building block in photonic integrated circuits via commercial foundry service.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2022
- Source ID
- 10.1038/s41467-022-29431-0
Entities
People
- Grigory Lihachev
- Jijun He
- Joel Guo
- John E. Bowers
- Junqiu Liu
- Lin Chang
- Miles Anderson
- Rui Ning Wang
- Tobias Kippenberg
- Wenle Weng
- Yang Liu
Organizations
- Air Force Office of Scientific Research
- Swiss National Science Foundation
- United States Department of Defense