Ipshita Datta

Postdoctoral Fellow

Columbia University in the city of New York

Ipshita Datta is currently and Engineering Pr at Columbia University a postdoctoral research scientist completed her graduate ofessor Michal Lipson ’ . She s group at Columbia University. She Chodorow postdoctoral fellow Center for degree Integrated in will be joining as May 2022 an Science from Urbanek in Professor Tony Heinz’s group in the Department of Applied Physics at Stanford University in September 2022. She has completed her Masters’ degree from material science with state Indian Institute of Technology Kharagpur (IIT), India. Her research focuses on merging the fields of oftheart nanophotonics to develop the next generation photonic 2D material hybrid platform that enables enhanced light-- matter interaction to probe the linear and nonlinear optical response of novel materials. She is intereste d in leveraging the strong light matter interaction in 2D materials with photonic structures to enable applications including data communication, 14 peerquantum computation, networking and sensing. reviewed journal and conference papers. She Ipshita Datta has published over also has 2 patent disclosures and serves as a reviewer for over 6 journals. 

Platform based on two-dimensional materials for next-generation integrated photonics

Despite significant advances in the field of integrated photonics, the predominant optical modulation scheme is intensity modulation (ON-OFF keying) that limits the optical bandwidth and detection error handling capabilities. One can extend the bandwidth and enhance detector sensitivity by encoding information in the phase of an optical signal with minimal intensity modulation. This necessitates an efficient phase modulator that can induce strong phase change with low optical loss. These phase modulators are the critical building blocks for other large-scale photonic systems including light detection and ranging (LIDAR), quantum and optical neural networks. Conventional phase modulators rely on either the slow, yet highly power consuming thermo-optic effect to induce pure phase change or the high loss plasma-dispersion effect that not only changes the phase and intensity of the optical signal in tandem. The need of the hour is a material or a device that can induce strong phase change with minimal absorption and capable of modulating at gigahertz of electro-optic bandwidth. Two dimensional (2D) materials such as transition metal dichalcogenides (TMDs) and graphene have been widely studied for their strongly tunable electro-optic properties; however, the regime of low-loss phase modulation remains largely unexplored. TMDs have been shown to experience massive change in their electro-optic response at excitonic resonances, where the optical loss is prohibitive for photonic applications. In our work, we probe the electro-optic properties of TMDs at transparency wavelengths suitable for telecom applications, and find that the doping induced change in the phase (Δn) is two orders of magnitude larger than the induced absorption (Δk). This metric |Δn Δk | for TMDs is 125, which is larger than that for silicon (~ 10 - 20) or graphene (~ 3.5), rendering TMDs an ideal alternative to conventional materials. We further demonstrate an ultracompact phase modulator based on graphene-TMD hybrid microring devices with low insertion loss and 10’s of GHz of electro-optic bandwidth. The ease of integration, strong light-matter interaction and large-scale growth of 2D materials enable their widespread applicability in emerging large-scale systems.