Seminar

Integrated photonics has emerged as the science of confining, guiding, trapping, manipulating, modulating, mixing, and detecting light - from millions of photons down to potentially the single photon limit. Now silicon and silicon nitride photonics form the backbone of optical communication systems beyond the fibre-optics-dominated era, taking advantage of the cost-effective surface-micromachining technology offered by the semiconductor manufacturing industry. Co-integration of passive optical circuits such as interferometers, etalons, travelling wave cavities, diffractive optics, etc., optoelectronic circuits such as photodetectors, amplifiers, feedback control loops, synchronizers and driver electronics and potential heterogenous integration of lasers brings a lot of functionality to the optical table (and also takes a lot of components off the optical table!). High local optical intensities enabled by tight optical confinement on chip, resonant enhancement in optical cavities, compact on-chip lattices of optical structures and higher order optical systems brings out interesting physics on the chip. The ability to bring together optical emitters, transparent waveguides, avalanche photodetectors, novel materials (2D materials, spintronics, epsilon-near-zero materials, piezoelectrics, etc.), artificial optical materials (metamaterials), makes integrated photonics interesting for ultra-sensitive studies of light-matter interaction in sub micron-scale control volumes.

Nanophotonic systems allow us to contrive clever ways of achieving coupling at the nanoscale. Strong photon-photon coupling at the few-photon scale is challenging to achieve for quantum technology development. However, strong coupling of photons with other physical systems such as phonons and spin holds strong potential for quantum technology. The comparatively longer lifetime of phonons also makes them interesting for memories, optical delays, and slow-light applications. Tight confinement of light on chip enables us to make on-chip optical tweezers that can move nano-mechanical structures, which in turn scatter the incident light, leading to strong coupling between light and mesoscale mechanical systems (containing < 1000 atoms along the smallest dimension). The strain in the mechanical structures also acts as a knob to tune the optical and optomechanical properties of the system. All this is made possible by Integrated Nano-Optomechanical Systems.

In this talk, I shall introduce the field of Integrated Nano-Optomechanical Systems comprising on-chip optical systems, movable nano-mechanical structures, and 2D materials. I shall describe the interactions between these systems and show results of interesting linear and nonlinear physics presented by these systems. I shall also show how these systems can be used for both classical and quantum applications such as optomechanical detectors and probes, reconfigurable photonics, memories, photonic computing, artificial photonic molecules and photonic condensed matter, on-chip atom optics, etc. and propose experiments that can be conducted towards these goals.