Daniel C. Cole, Jordan R. Stone, Miro Erkintalo, Ki Youl Yang, Xu Yi, Kerry J. Vahala, and Scott B. Papp. 2018. “
Kerr-microresonator solitons from a chirped background.” Optica, 5, 10, Pp. 1304–1310.
Publisher's VersionAbstractOptical frequency combs based on solitons in nonlinear microresonators open up new regimes for optical metrology and signal processing across a range of expanding and emerging applications. In this work, we advance these combs toward applications by demonstrating protected single-soliton formation and operation in a Kerr-nonlinear microresonator using a phase-modulated pump laser. Phase modulation gives rise to spatially/temporally varying effective loss and detuning parameters, leading to an operation regime in which multi-soliton degeneracy is lifted and a single soliton is the only observable behavior. We achieve direct, on-demand excitation of single solitons as indicated by reversal of the characteristic &\#x201C;soliton step.&\#x201D; Phase modulation also enables precise, high bandwidth control of the soliton pulse train&\#x2019;s properties, and we measure dynamics that agree closely with simulations. We show that the technique can be extended to high-repetition-frequency Kerr solitons through subharmonic phase modulation. These results will facilitate straightforward generation and control of Kerr-soliton microcombs for integrated photonics systems.
Ki Youl Yang, Dong Yoon Oh, Seung Hoon Lee, Qi-Fan Yang, Xu Yi, Boqiang Shen, Heming Wang, and Kerry Vahala. 2018. “
Bridging ultrahigh-Q devices and photonic circuits.” Nature Photonics, 12, 5, Pp. 297–302.
Publisher's VersionAbstractOptical microresonators are essential to a broad range of technologies and scientific disciplines. However, many of their applications rely on discrete devices to attain challenging combinations of ultra-low-loss performance (ultrahigh Q) and resonator design requirements. This prevents access to scalable fabrication methods for photonic integration and lithographic feature control. Indeed, finding a microfabrication bridge that connects ultrahigh-Q device functions with photonic circuits is a priority of the microcavity field. Here, an integrated resonator having a record Q factor over 200 million is presented. Its ultra-low-loss and flexible cavity design brings performance to integrated systems that has been the exclusive domain of discrete silica and crystalline microcavity devices. Two distinctly different devices are demonstrated: soliton sources with electronic repetition rates and high-coherence/low-threshold Brillouin lasers. This multi-device capability and performance from a single integrated cavity platform represents a critical advance for future photonic circuits and systems.Using silicon nitride waveguides processed by plasma-enhanced chemical vapour deposition, full integration of ultrahigh-Q resonators with other photonic devices is now possible, representing a critical advance for future photonic circuits and systems.
Xu Yi, Qi-Fan Yang, Ki Youl Yang, and Kerry Vahala. 2018. “
Imaging soliton dynamics in optical microcavities.” Nature Communications, 9, 1, Pp. 3565.
Publisher's VersionAbstractSolitons are self-sustained wavepackets that occur in many physical systems. Their recent demonstration in optical microresonators has provided a new platform for the study of nonlinear optical physics with practical implications for miniaturization of time standards, spectroscopy tools, and frequency metrology systems. However, despite its importance to the understanding of soliton physics, as well as development of new applications, imaging the rich dynamical behavior of solitons in microcavities has not been possible. These phenomena require a difficult combination of high-temporal-resolution and long-record-length in order to capture the evolving trajectories of closely spaced microcavity solitons. Here, an imaging method is demonstrated that visualizes soliton motion with sub-picosecond resolution over arbitrary time spans. A wide range of complex soliton transient behavior are characterized in the temporal or spectral domain, including soliton formation, collisions, spectral breathing, and soliton decay. This method can serve as a visualization tool for developing new soliton applications and understanding complex soliton physics in microcavities.
Nicolas Volet, Xu Yi, Qi-Fan Yang, Eric J Stanton, Paul A Morton, Ki Youl Yang, Kerry J Vahala, and John E Bowers. 2018. “
Micro-resonator soliton generated directly with a diode laser.” Laser and Photonics Reviews, 12, 5, Pp. 1700307.
Publisher's Version Daryl T Spencer, Tara Drake, Travis C Briles, Jordan Stone, Laura C Sinclair, Connor Fredrick, Qing Li, Daron Westly, Robert B Ilic, Aaron Bluestone, Nicolas Volet, Tin Komljenovic, Lin Chang, Seung Hoon Lee, Dong Yoon Oh, Myoung-Gyun Suh, Ki Youl Yang, Martin HP Pfeiffer, Tobias J Kippenberg, Erik Norberg, Luke Theogarajan, Kerry Vahala, Nathan R Newbury, Kartik Srinivasan, John E Bowers, Scott A Diddams, and Scott B Papp. 2018. “
An optical-frequency synthesizer using integrated photonics.” Nature, 557, 7703, Pp. 81–85.
Publisher's Version Xinbai Li, Boqiang Shen, Heming Wang, Ki Youl Yang, Xu Yi, Qi-Fan Yang, Zhiping Zhou, and Kerry Vahala. 2018. “
Universal isocontours for dissipative Kerr solitons.” Optics Letters, 43, 11, Pp. 2567–2570.
Publisher's VersionAbstractDissipative Kerr solitons can be generated within an existence region defined on a space of normalized pumping power versus cavity-pump detuning frequency. The contours of constant soliton power and constant pulse width in this region are studied through measurement and simulation. Such isocontours impart structure to the existence region and improve understanding of soliton locking and stabilization methods. As part of the study, dimensionless, closed-form expressions for soliton power and pulse width are developed (including Raman contributions). They provide isocontours in close agreement with those from the full simulation, and, as universal expressions, can simplify the estimation of soliton properties across a wide range of systems.