Broadband electro-optic frequency comb generation in a lithium niobate microring resonator

By Mian Zhang, B. Buscaino, Cheng Wang, Amirhassan Shams-Ansari, C. Reimer, Rongrong Zhu, Joseph M. Kahn, Marko Loncar. Nature, 2018

843 citations recorded by the source corpus.

Optical frequency combs consist of equally spaced discrete optical frequency components and are essential tools for optical communication, precision metrology, timing and spectroscopy1–9. At present, combs with wide spectra are usually generated by mode-locked lasers10 or dispersion-engineered resonators with third-order Kerr nonlinearity11. An alternative method of comb production uses electro-optic (EO) phase modulation in a resonator with strong second-order nonlinearity, resulting in combs with excellent stability and controllability12–14. Previous EO combs, however, have been limited to narrow widths by a weak EO interaction strength and a lack of dispersion engineering in free-space systems. Here we overcome these limitations by realizing an integrated EO comb generator in a thin-film lithium niobate photonic platform that features a large EO response, ultralow optical loss and highly co-localized microwave and optical fields15, while enabling dispersion engineering. Our measured EO comb spans more frequencies than the entire telecommunications L-band (over 900 comb lines spaced about 10 gigahertz apart), and we show that future dispersion engineering can enable octave-spanning combs. Furthermore, we demonstrate the high tolerance of our comb generator to modulation frequency detuning, with frequency spacing finely controllable over seven orders of magnitude (10 hertz to 100 megahertz), and we use this feature to generate dual-frequency combs in a single resonator. Our results show that integrated EO comb generators are capable of generating wide and stable comb spectra. Their excellent reconfigurability is a powerful complement to integrated Kerr combs, enabling applications ranging from spectroscopy16 to optical communications8. Using a thin-film lithium niobate photonic platform, an electro-optic frequency comb generator is realized that is capable of producing wide and stable spectra, spanning more frequencies than the entire telecommunications L-band.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/f1cc7022c18ab3c6cbdd708c4d8d2a941b2583a8

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

Integrated electro-optics on thin-film lithium niobate (2024, neutral): “Single-cavity devices can be achieved by placing a PM inside a cavity 2,14 .”
High-efficiency and broadband on-chip electro-optic frequency comb generators (2021, positive): “Electro-optic (EO) modulation provides an attractive alternative to OFC generation 9–12 , 21– 23 .”
Advances in lithium niobate photonics: development status and perspectives (2022, background): “It is also worth mentioning that the strong EO effect of LN can not only be used for realizing high performance modulators but it can also be used for other areas where EO modulation shows advantages, such as the EO frequency comb.(77) Some more examples can be found in Sec.”
Reduced Material Loss in Thin-film Lithium Niobate Waveguides (2022, background): “For instance, the bandwidth of electro-optic (EO) frequency combs [2] and the efficiency of microwave-to-optical transducers [3, 4] are proportional to the resonator quality factor Q or (loss rate).”