EPSRC-SFI:Towards power efficient microresonator frequency combs

Optical frequency combs consisting of hundreds and thousands of equally spaced narrow resonance lines have been demonstrated in the 1990s, and their discovery was awarded the Nobel Prize in 2005. In the past decade, this research field has witnessed outstanding progress through the development of microresonator technology and observation and exploitation of the microresonator frequency combs - microcombs.

For light, microresonators act as miniature racetracks, with photons zipping around the circle in loops. The infinite path length and a small footprint are the key advantages of the on-chip frequency conversion. Microcombs are emerging as a disruptive technology for realizing precision metrology, spectroscopy, waveform synthesis and optical processing of information realisable in the small footprint and chip-scale platforms. One of many striking application examples comes from astronomical research, where combs were used to search for exoplanets.

The research programme proposed by the University of Bath and Trinity College Dublin aims to develop the next generation of the microresonator systems with enhanced efficiency and flexible repetition rates to drive future applications of comb sources. The proposal cuts across the UK EPSRC research areas of Optical Devices and Subsystems; Light-Matter Interaction and Optical Phenomena; RF & Microwave Devices; and Nonlinear Systems. These areas and specific research tasks of the project contribute to the EPSRC Productive, Connected, and Resilient Nation Outcomes. In Ireland, the project aligns well with the National Priority area Future Networks, Communications and Internet of Things that explicitly seeks to develop novel photonic devices to power the communications systems of the coming decade with ever improving energy efficiency.