KNI Distinguished Seminar with Marko Loncar of Harvard University | March 6, 2019

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Professor Marko Loncar of Harvard University will give the second KNI Distinguished Seminar on Wednesday, March 6.

Marko Loncar - KNI Distinguished Seminar - March 6 2019

February 25, 2019

Update: Watch Marko Loncar's full KNI Distinguished Seminar here.

Marko Loncar, Tiantsai Lin Professor of Electrical Engineering at Harvard's John A Paulson School of Engineering and Applied Sciences (SEAS) and Caltech alumnus, will present a talk on "New Opportunities with Old Optical Materials" at the next KNI Distinguished Seminar on Wednesday, March 6th at 3 pm at 100 Broad (Rock Audtorium). Following the talk, there will be a light reception in the adjacent patio space of the Beckman Institute.

For more information on the KNI Distinguished Seminar Series, see here.


Marko Loncar is Tiantsai Lin Professor of Electrical Engineering at Harvard's John A Paulson School of Engineering and Applied Sciences (SEAS), as well as Harvard College Professor. Loncar received his Diploma from University of Belgrade (R. Serbia) in 1997, and his PhD from Caltech in 2003 (with Axel Scherer), both in Electrical Engineering. After completing his postdoctoral studies at Harvard (with Federico Capasso), he joined SEAS faculty in 2006. Loncar is expert in nanophotonics and nanofabrication, and his current research interests include quantum and nonlinear nanophotonics, quantum optomechanics, high-power optics, and nanofabrication. He has received NSF CAREER Award in 2009 and Sloan Fellowship in 2010. In recognition of his teaching activities, Loncar has been awarded Levenson Prize for Excellence in Undergraduate Teaching (2012), and has been named Harvard College Professor in 2017. Loncar is fellow of Optical Society of America, and Senior Member of IEEE and SPIE.


Lithium niobate (LN) is an "old" material with many applications in optical and microwave technologies, owing to its unique properties that include large second order nonlinear susceptibility, large piezoelectric response, and wide optical transparency window. Conventional LN components, including modulators and periodically polled frequency converters, have been the workhorse of the optoelectronic industry. They are reaching their limits, however, as they rely on weakly guiding ion-diffusion defined optical waveguides in bulk LN crystal. I will discuss our efforts aimed at the development of integrated LN platform, featuring sub-wavelength scale light confinement and dense integration of optical and electrical components, that has the potential to revolutionize optical communication networks and microwave photonic systems, as well as enable realization of quantum photonic circuits. Good example is our recently demonstrated integrated LN electro-optic modulator that can be driven directly by a CMOS circuit [1], that supports data rates > 200 gigabits per second with > 90% optical transmission efficiency. I will also discuss our work on ultra-high Q LN optical cavities (Q ~ 10,000,000) [2] and their applications [3 - 5], as well as nonlinear wavelength conversion using periodically poled LN films [6].

Diamond is another "old" material with remarkable properties! It is transparent from the ultra-violet to infrared, has a high refractive index, strong optical nonlinearity and a wide variety of light-emitting defects of interest for quantum communication and computation. In my talk, I will summarize our efforts towards the development of integrated diamond quantum photonics platform aimed at realization of efficient photonic and phononic interfaces for diamond spin qubits [7-12].


1. C. Wang, M. Zhang, X. Chen, M. Bertrand, A. Shams-Ansari, S. Chandrasekhar, P. Winzer, and M. Lončar. "Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages." Nature, 562, 101 (2018)
2. M. Zhang, C. Wang, R.  Cheng, A. Shams-Ansari, and M. Lončar, "Monolithic Ultrahigh-Q Lithium Niobate Microring Resonator." Optica, 4, 1536 (2017).
3. M. Zhang, B. Buscaino, C. Wang, A. Shams-Ansari, C. Reimer, R. Zhu, J. Kahn, and M. Lončar. "Broadband electro-optic frequency comb generation in an integrated microring resonator." arXiv:1809.08636
4. C. Wang, M. Zhang, R. Zhu, H. Hu, and M. Lončar. "Monolithic photonic circuits for Kerr frequency comb generation, filtering and modulation." arXiv:1809.08637
5. M. Zhang, C. Wang, Y. Hu, A. Shams-Ansari, T. Ren, S. Fan, and M. Lončar. "Electronically Programmable Photonic Molecule." Nature Photonics, 13, 36 (2019)
6. C. Wang, C. Langrock, A. Marandi, M. Jankowski, M. Zhang, B. Desiatov, M. M. Fejer, and M. Lončar. "Ultrahigh-efficiency wavelength conversion in nanophotonic periodically poled lithium niobate waveguides." Optica, 5, 1438 (2018)
7. B. Machielse, S. Bogdanovic, S. Meesala, S. Gauthier, M. J. Burek, G. Joe, M. Chalupnik, Y. I. Sohn, J. Holzgrafe, R. Evans, C. Chia, H. Atikian, M. K. Bhaskar, D. D. Sukachev, L. Shao, S. Maity, M. D. Lukin, and M. Lončar, "Electromechanical control of quantum emitters in nanophotonic devices", arXiv: 1901.09103 (2019)
8. R. E. Evans, M. K. Bhaskar, D. D. Sukachev, C. T. Nguyen, A. Sipahigil, M. J. Burek, B. Machielse, G. H. Zhang, A. S. Zibrov, E. Bielejec, H. Park, M. Lončar, and M. D. Lukin  "Photon-mediated interactions between quantum emitters in a diamond nanocavity." Science, 362, 662 (2018)
9. Y. I. Sohn*, S. Meesala*, B. Pingault*, H. A. Atikian, J. Holzgrafe, M. Gündoğan, C. Stavrakas, M. J. Stanley, A. Sipahigil, J. Choi, M. Zhang, J. L. Pacheco, J. Abraham, E. Bielejec, M. D. Lukin, M. Atatüre, and Marko Lončar. "Controlling the coherence of a diamond spin qubit through its strain environment." Nature Communications, 9, 2012 (2018)
10. M. J. Burek, C. Meuwly, R. E. Evans, M. K. Bhaskar, A. Sipahigil, S. Meesala, D. D. Sukachev, C. T. Nguyen, J. L. Pacheco, E. Bielejec, M. D. Lukin, and M. Lončar, "A fiber-coupled diamond quantum nanophotonic interface." Phys. Rev. Applied, 8, 024026 (2017)
11. M. J. Burek, J. D. Cohen, S. M. Meenehan, T. Ruelle, S. Meesala, J. Rochman, H. A. Atikian, M. Markham, D. J. Twitchen, M. Lukin, O. J. Painter, and M. Lončar, "Diamond optomechanical crystals." Optica, 12, 1404  (2016)
12. A. Sipahigil, R.E. Evans, D.D. Sukachev, M.J. Burek, J. Borregaard, M.K. Bhaskar, C.T. Nguyen, J.L. Pacheco, H.A. Atikian, C. Meuwly, R.M. Camacho, F. Jelezko, E. Bielejec, H. Park, M. Lončar, and M.D. Lukin, "An integrated diamond nanophotonics platform for quantum optical networks", Science, 6314, (2016)