Theory and simulation of generation of frequency combs in micro-resonators

Frequency combs are spectra consisting of a series of discrete, equally spaced elements and form the modern standard of optical frequencies and clocks. Frequency combs led to the Nobel Prize in Physics to John Hall and Theodor Hänsch in 2005. Micro-resonator-based frequency combs have attracted a lot of attention for their potential applications in precision metrology, gas sensing, arbitrary optical waveform generation, quantum technologies, telecommunication and integrated photonic circuits. Micro-resonator combs are generated in ultra-high-Q optical resonators that enable the confinement of extremely high optical power levels in very small 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. Dr. Pascal Del'Haye of the Optical Frequency Standard section of NPL directed by Dr. Patrick Gill has developed and optimised micro-resonator frequency combs based on periodic and soliton like wave-forms of the light circulating in the optical cavity. These are the temporal counterparts of periodic and cavity-soliton solutions discovered and analysed in the Computational Nonlinear and Quantum Optics (CNQO) group at Strathclyde for more than ten years. The project develops, optimises, and strategically compares accurate mathematical models for the generation of frequency combs in micro-resonators in a close connection with the experiments performed at NPL in Dr. Del'Haye's laboratory.

The project will run in a close collaboration between Strathclyde and NPL. The CNQO group at Strathclyde is in a unique and strategic position world-wide being the inventor of the theory and first developer of the simulations associated with cavity-solitons, the key elements of the optimal frequency-comb generation using resonators. Dr. Del'Haye will be the external supervisor of the PhD student who will periodically visit NPL and compare the results of the simulations and theoretical models with the experimental data.