Smart photonic designs for next generation Kerr frequency combs – SMARTKOMBS

Lasers have revolutionized our civilization, allowing us to communicate faster, to probe and cool atoms, or to measure time and distance with unprecedented precision. These advances have been made possible by optical frequency combs, which establish a direct and coherent link between the optical domain and radio frequencies. One of the methods of comb generation, called 'Kerr combs', is based on cascaded four-wave mixing frequency conversion in a passive non-linear cavity driven by a coherent laser. A mode-locking regime is possible, thanks to the generation of solitons in the cavity. These pulses preserve their shape by balancing the dispersion by the nonlinearity of the optical index. However, traditional optical cavities focus mainly on anomalous second order dispersion (group velocity dispersion, GVD) and avoiding multimode effects.

The proposed project is a 42-month endeavor, focused on exploring new paradigms for Kerr comb generation. The goal is to develop innovative photonic architectures with complex dispersion and dissipation control or multimode cavities to realize `exotic' dissipative Kerr solitons -- or more generally, self-localized light patterns. We will introduce additional degrees of freedom of intra- or inter-cavity couplings to allow a spectral shaping of the comb, and will study the associated dynamics, opening perspectives for the emergence of new phenomena, thereby advancing our understanding of fundamental nonlinear physics. While these systems will be initially modeled using rigorous equations, the project will then rely on artificial intelligence (machine learning) tools to chart these previously unexplored parameter regimes. Experimental demonstrations will be realized in optical fiber waveguide cavities to validate the principles, and propose future implementations with integrated photonics. The developed machine learning models will also be used for inverse-design approaches to optimize the generation of coherent Kerr combs with custom on-demand properties. This fundamental knowledge will be useful for applications in numerous fields, such as optical communication, frequency metrology, spectroscopy, and ranging.