Research Projects

Manipulating light transport in discrete waveguide lattices is a fascinating field of research with great promise for the discovery of novel fundamental science as well as its implications for advances in optical devices. In this project, we shall use femtosecond laser writing for developing such three-dimensional waveguide arrays where a Schrödinger-like equation governs the propagation of optical fields. Specifically, inspired by the field of condensed matter and quantum physics, we plan to implement a tunable synthetic magnetic flux in waveguide lattices. We shall exploit Floquet engineering (i.e., applying a time-periodic driving to a static system) to realize complex-valued hopping amplitude in two-dimensional tight-binding lattices. The idea is to go beyond the capability and scope of the well-established solid-state electronic systems and explore novel physics in our integrated photonic platform. Our preliminary numerical simulations indicate topological phase transitions and back-scatter immune robust topological edge states in such laser-written structures. Note that all previous experiments in this field were carried out using modulated waveguide structures where the net magnetic flux was zero. In addition to the realization of magnetic flux for photons, we plan to study the role of optical Kerr nonlinearity (analogous to the mean-field bosonic interactions) and disorder in these photonic systems. We shall access optical nonlinearity by launching intense laser pulses, and the controllable disorder can be implemented by the laser-writing technique. The proposed work will be of great national/international importance opening an exciting route towards exploring quantum Hall like states and topological physics in our photonic platform.