University of Ottawa

Purpose

Exceptional points are branch point singularities of self-intersecting Riemann sheets, which can be observed in a non-Hermitian system with complex eigenvalues. In optics, there have been a diversity of intriguing effects based on exceptional points, e.g. loss induced transparency, lasing, and unidirectional reflection. When adiabatically changing the parameters of a system around an exceptional point in parametric space, the initial eigenstate will transfer to another while gaining a geometric phase. Recently, Berini’s group demonstrated mode transfer by dynamically encircling exceptional points in coupled dielectric waveguides at optical telecommunication wavelengths and have shown that encircling a moving exceptional point provides a new scheme to optimize performance, diminish length and insertion loss, while maintaining the topological properties of the operation. These concepts will be further explored in silicon photonics implementations, in particular subwavelength metamaterial waveguides as pioneered by the NRC silicon photonics group, as well as in metasurfaces and nanoplasmonic systems. The technology developed in the collaborative research project would constitute a substantial advance in the field and contribute to making Canada a global leader in emerging quantum photonics sensor technologies.