Epsilon-Near-Zero Material based Nanophotonic Metamaterials for Modulation of Optical Intensity and Polarization

Advancement of photonic technologies has led to achieve active control of electromagnetic properties (viz. amplitude, phase, and polarization) of light. Active manipulation of reflected or transmitted light can be done with external stimuli such as electrical biasing — leading to electro-optic modulation. Conventional free-space electro-optic modulators face the limitation posed by the small electro-optic coefficients of natural materials. The modulators are bulky and require high voltage bias, making them unsuitable for nanophotonic applications. This motivated one to explore ultra-compact low-voltage alternative for nanophotonic modulators based on artificially-engineered materials or ‘metamaterials’. Metamaterial based electro-optic modulators incorporating transparent conducting oxides (TCOs) have gained ample attention due to exceptional electro-optic properties at telecommunication wavelengths. Tuning the optical properties of TCOs allows exploring an exciting phenomenon called ‘epsilon-near-zero (ENZ) effect’, where the real part of permittivity becomes vanishingly small at a certain wavelength. The ENZ-effect can be harnessed by controlling accumulation of the free-carriers of TCOs (using electrical biasing) while configured in a metal-oxide-semiconductor type structure. This webinar presents the opportunities and challenges in achieving efficient electro-optic intensity and phase modulation for nanophotonics using the ENZ effect in TCO-based resonant metamaterials.

Subject Matter Level: Intermediate - Assumes basic knowledge of the topic

What You Will Learn:
• Fundamentals of TCO-based metamaterial modulators based on epsilon-near-zero (ENZ) effect
• Design opportunities and challenges in achieving efficient intensity and phase modulation using ENZ-enabled resonant nanophotonic platforms

Who Should Attend:
• MSc, M.Tech and PhD students from Optics, Photonics, Optoelectronics, and Electronics background
• Researchers from Academia and Industry working on electro-optic modulators

About the Presenter: Debabrata Sikdar from IIT Guwahati, India

Dr. Debabrata Sikdar is an Associate Professor in Dept of EEE at IIT Guwahati. He earned his UG (2008) and PG (2012) from BITS Pilani, with experience at General Electric (2008–2010). Awarded the 2012 Victoria India Doctoral Scholarship, he completed his PhD in Nanophotonic Engineering at Monash University, Australia (2015), followed by postdoctoral research in nanoplasmonics at Imperial College London (ICL) before joining IITG in 2017. His research focuses on applied nanophotonics and metamaterials, including smart windows and radiative cooling, electro-tunable modulators, and topological photonics for 6G. Notable accolades include the 2016 Douglas Lampard Electrical Engineering Prize for the outstanding PhD thesis at Monash, a Marie Curie Fellowship at ICL, and recognition as an Emerging Leader 2023 by J. Phys.: Cond. Matt. (IOP). As a member of Optica, OSI, IEEE, and SPIE he has authored over 90 journal articles (>2,700 citations), 2 book chapters, 8 patents, and delivered 50+ talks