Abstract
Large-scale, electronically reconfigurable photonic integrated circuits (PICs) can enable programmable gate array (PGA) to realize extremely fast, arbitrary linear operations, with potential applications in classical and quantum optical information technology. The basic building blocks of existing PGAs are thermally tunable broadband Mach-Zehnder-Interferometers, which pose several limitations in terms of size, power, and scalability. Chalcogenide-based phase change materials (PCMs), exhibiting large nonvolatile change in the refractive index, can potentially transform these devices, providing at least one order of magnitude reduction in the device size, zero static energy consumption, and minimal cross-talk. In this talk, I will discuss different PCMs that can be used in conjunction with silicon and silicon nitride photonics, to create reconfigurable optical switches for visible and infrared wavelengths [1-5]. I will also talk about different heaters that are needed to actuate the phase transitions on-chip. Specifically, I will show how using ultrathin graphene as a heater element can provide very high energy-efficiency, close to the fundamental limit set by thermodynamics.
Bio
Arka Majumdar is an associate professor in the departments of Electrical and Computer Engineering and of Physics at the University of Washington (UW). He received B. Tech. from IIT-Kharagpur (2007), where he was honored with the President’s Gold Medal. He completed his MS (2009) and Ph.D. (2012) in Electrical Engineering at Stanford University. He spent one year at the University of California, Berkeley (2012-13), and then in Intel Labs (2013-14) as postdoc before joining UW. His research interests include developing a hybrid nanophotonic platform using emerging material systems for optical information science, imaging, and microscopy. Prof. Majumdar is the recipient of multiple Young Investigator Awards from the AFOSR (2015), NSF (2019), ONR (2020) and DARPA (2021), Intel early career faculty award (2015), Amazon Catalyst Award (2016), Alfred P. Sloan fellowship (2018), UW college of engineering outstanding junior faculty award (2020), iCANX Young Scientist Award (2021) and IIT-Kharagpur Young Alumni Achiever Award (2022). He is co-founder and technical advisor of Tunoptix, a startup commercializing software defined meta-optics.
