Microresonator-based frequency combs ("microcombs") have attracted a lot of attention for their potential applications in precision metrology, gas sensing, arbitrary optical waveform generation, telecommunication and integrated photonic circuits. Microcombs are generated in ultra-high-Q optical resonators that enable the confinement of extremely high optical power levels in tiny mode-volumes. The high optical power densities lead to the conversion of a continuous wave laser into a comb of equidistant optical modes that can be used like a ruler for optical frequency measurements. This talk presents new results in the field of microresonator-based frequency combs, which are a promising candidate to realize out-of-the-lab applications for this technology. The second part of the talk presents results on optically induced symmetry breaking between counter-propagating light in microresonators. This effect shows that microresonators can act as nonreciprocal devices that transmit light in one direction but not in the other. The symmetry breaking can be used for optical diodes, circulators and for the development of integrated optical gyroscopes.

报告人简介：Pascal Del'Haye received his PhD 2011 from the University of Munich and the Max Planck Institute of Quantum Optics for pioneering work on optical frequency comb generation in microresonators. After his PhD, Pascal spent 4 years at the National Institute of Standards and Technology (NIST) in Boulder CO, USA. Since 2015 he is leading the microphotonics research group at the UK's National Physical Laboratory (NPL) south-west of London. For his work on nonlinear photonics and optical frequency metrology, Pascal received several awards and prizes, including the Helmholtz prize for metrology, the EPS QEOD thesis prize and the EFTF Young Scientist Award.