Information processing and communication are at the heart of many technologies that enable modern life. These technologies have experienced exponential growth over the past several decades, thanks to the aggressive scaling of electronic devices. Next-generation information technologies, however, cannot be supported by only scaling transistors, and will rely heavily on data centers and cloud computing to drive performance improvements. We are already experiencing this trend with the increased investment from large technology companies in these sectors. To support this architecture, we need to bring optical interconnect technology (i.e., fiber optics), which is the backbone of the modern internet, to shorter length scales. Going beyond classical computing and communication technologies, quantum mechanics presents an opportunity to realize a paradigm shift in information technology. All these technologies, however, require ultra-low power optoelectronic devices; the power requirement is almost four orders of magnitude lower than that of existing devices. In my research, I aim to create these devices using atomically thin materials integrated with silicon nitride photonic circuits. Specifically, we aim to develop an optical modulator and optical switch, that can change light transmission using minimal power. These devices will be fabricated using well-developed semiconductor manufacturing technology. Along with developing new technology, the proposal aims to incorporate a design-build-test module in existing lecture-based nanophotonics courses to provide hands-on experience to the next-generation knowledge workers in the field of integrated photonics.
Ultra-low-power tunable and nonlinear optical devices hold the key for numerous optical technologies including optoelectronic information processing, communication, and photonic quantum simulations of strongly correlated materials. Currently, the power required to modulate the light transmission through photonic devices or to observe a nonlinear input-output response is too high. This power can be reduced by spatially confining the electronic and photonic wave functions to a nanometer-length scale for an extended period of time. Nanophotonic resonators integrated with emerging low-dimensional materials present an attractive platform to create ultra-low-power optoelectronic devices. To that end, this proposal aims to integrate van der Waals (vdW) materials (e.g., graphene or transition metal dichalcogenides) and their heterostructures with silicon nitride nano-resonators. The choice of silicon nitride is motivated by its large bandgap and compatibility with large-scale semiconductor manufacturing. The vdW materials are chosen for their unique quantum properties, large exciton binding energies, and atomic thinness that enable extremely small active volumes and unprecedented material compatibility; they can be transferred onto any substrate without requiring explicit lattice matching. Combining numerical simulation, device fabrication, and optical characterization, three research aims will be pursued: (i) develop an experiment-driven model for vdW material?cavity coupling; (ii) demonstrate optical nonlinearity at the few photon level in a coupled cavity array, and (iii) create an electro-optic modulator with attojoule electrical energy per switching. While the initial applications of these devices will be in ultra-low-power classical optical information science, the same platform can be used for developing quantum technologies, including quantum many-body simulations and quantum signal transduction.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
