Bhagwat Singh Chouhan

About Me

Bhagwat Singh Chouhan working in the laboratory

I am a postdoctoral researcher at the Énergie, Matériaux et Télécommunications (EMT) centre of the Institut national de la recherche scientifique (INRS‑EMT) in Canada, focusing on tunable metawaveguides for terahertz communication systems. I completed my Ph.D. in Physics (2020‑2025) at the Indian Institute of Technology (IIT) Guwahati, where I specialized in non‑linear optics and photonics. My academic journey includes a B.Sc. in Physics from the Regional Institute of Education, Bhopal, and an M.Sc. in Physics from IIT Guwahati.

My research targets the terahertz gap by designing active and passive metamaterials that enable broadband, polarization‑insensitive, and tunable responses. This includes planar and multi‑stacked structures incorporating phase‑transition materials such as VO₂, perovskites and machine‑learning‑optimized designs for next‑generation communication and sensing applications. I have hands‑on experience building a terahertz time‑domain spectroscopy setup and mastering cleanroom fabrication techniques like electron beam lithography, photolithography and thin‑film deposition.

Postdoctoral Researcher at INRS‑EMT (2025–Present)
Ph.D. Physics, IIT Guwahati (2020‑2025)
M.Sc. Physics, IIT Guwahati (2017)
B.Sc. Physics, RIE Bhopal (2015)
Best Poster Awards at FTTA‑2021 & WRAP‑2022
Vice President, IEEE Photonics Society Student Chapter (2022‑24)

Research & Experience

Over five years of theoretical and experimental research on terahertz metamaterials, I design, fabricate and characterize novel devices that bridge the terahertz gap. My work encompasses planar filters, toroidal metasurfaces and multi‑stacked metamaterials with active tunability. I integrate semiconductors and phase‑transition materials to achieve tunable broadband responses, explore phenomena such as electromagnetically induced transparency and phonon‑polariton‑induced Rabi splitting, employ machine learning for optimization and, more recently, investigate tunable metawaveguide designs for terahertz communication systems.

Designed and fabricated planar metamaterials, including filters, toroidal structures and bound‑state‑in‑continuum devices.
Investigated multi‑resonator coupling and phonon‑polariton induced Rabi splitting in perovskite‑based metamaterials.
Engineered tunable multi‑stacked hybrid metamaterials using VO₂, perovskite and Bi₂Se₃ for ultra‑broadband terahertz response.
Applied machine‑learning algorithms to optimize metamaterial designs and predict performance.
Built a custom terahertz time‑domain spectroscopy (THz‑TDS) setup for experimental characterization.
Published nine peer‑reviewed journal articles and presented five conference papers; filed a patent on an ultra‑broadband actively tunable THz modulator.
Contributed to national research proposals for broadband THz modulation (ISPEC‑2024) and THz plasmon dynamics (IUAC‑2024).
Currently exploring tunable metawaveguide designs for terahertz communication systems to support next‑generation 6G applications.

Publications

Journal Articles

Ultra‑broadband actively tunable terahertz modulator based on multi‑stacked metamaterial, Scientific Reports 15(1), 2025.
Broadening of resonance with the bending of strongly coupled strip resonators in a planar terahertz metamaterial, Journal of Lightwave Technology 42, 3283 (2024).
Multi‑stacked polarization‑insensitive broadband terahertz metamaterial, Journal of Applied Physics 135, 173103 (2024).
Machine learning‑driven ultra‑broadband terahertz multilayer metamaterial, Journal of Lightwave Technology, 2024 (doi: 10.1109/JLT.2024.3509492).
Terahertz binary computing in a coupled toroidal metasurface, Scientific Reports 14, 8721 (2024).
Single and dual‑band electromagnetically induced transparency in a strongly near‑field coupled planar toroidal terahertz metamaterial, Optics & Laser Technology 176, 111006 (2024).
Polarization‑independent lattice‑coupled terahertz toroidal excitation, Journal of Physics D: Applied Physics 56, 415101 (2023).
Tunable terahertz absorption modulation in graphene nanoribbon‑assisted dielectric metamaterial, Journal of Physics D: Applied Physics 55, 285101 (2022).
Ultra‑broadband actively tunable terahertz modulator based on multi‑stacked metamaterial, Optics & Laser Technology (under review).
Dynamic control of electromagnetically induced transparency using thermal effects via flexible terahertz metasurface, IEEE Journal of Selected Topics in Quantum Electronics (under review).
Phonon‑polaritons mediated dual electromagnetically induced transparency in a THz metamaterial, ACS Photonics (under review).
Electromagnetically induced transparency in a strongly coupled orthogonal polarization‑insensitive planar terahertz metamaterial, Journal of Physics D: Applied Physics 57, 075103 (2024).

Conference Contributions

Modulating broadband terahertz in a graphene‑assisted dielectric metamaterial, Workshop on Recent Advances in Photonics (WRAP‑2022).
Graphene‑dielectric based tunable terahertz polarization‑insensitive modulator, IEEE Photonics Conference 2022.
Polarization‑insensitive ultra‑broadband terahertz metamaterials for 6G applications, META‑2024.
Electromagnetically induced transparency in broadside‑coupled toroidal metasurfaces, WRAP‑2024.
Metamaterial‑based terahertz broadband active modulator using VO₂‑resonators for 6G communication systems, RIC Conclave 2024 (accepted).

Patent

Title: Ultra‑broadband actively tunable terahertz modulator based on multi‑stacked metamaterial and a method of preparation (Application No. 202431065). Status: early publication completed and under examination.

Professional Experience

Doctoral Researcher

Indian Institute of Technology, Guwahati (2020–2025)

Main investigator of projects on terahertz metamaterials, responsible for developing a THz‑TDS laboratory, and initiating collaborations. Published multiple peer‑reviewed papers and filed a patent.

Research Project Student

Indian Institute of Technology, Guwahati (2015–2017)

Investigated electro‑optical properties of photochromatic bio‑nano hybrids during master’s studies, exploring optical doping and charge transport dynamics in thin films.

Leadership & Teaching

Vice President (2022‑24) and Secretary (2020‑22) of the IEEE Photonics Society Student Chapter at IIT Guwahati. Assisted with postgraduate physics laboratory courses and mentored undergraduate and graduate students in terahertz and metamaterials research.

Events & Activities

Conferences (selected)

IEEE Silicon Photonics (London, 2025).
Photonics‑2024 (16th International Conference on Fiber Optics and Photonics).
QMAT‑2024 (7th Annual Conference on Quantum Condensed Matter).
Research & Industrial Conclave (RIC‑2024), IIT Guwahati.
META‑2024 (14th International Conference on Metamaterials, Photonic Crystals and Plasmonics).
ISPEC‑2024 (India Semiconductor and Packaging Ecosystem Conference).
ICANN‑2023 (International Conference on Advanced Nanomaterials & Nanotechnology).
IFCFPM‑2023 (Indo‑French Conference on Photonics and Metamaterials).
RIC‑2022, IPC‑2022, FTTA‑2021.

Workshops & Schools

Workshop on Advancements and Applications of Analytical Instruments (AAAI‑2024).
INUP‑2022: Indian Nanoelectronics Users Program.
IEEE Sensors Winter School 2023.
ICTP Winter College on Optics: Terahertz Optics and Photonics (2023).

Symposiums & Meetings

Frontiers in Optics & Terahertz Photonics (FiOTP‑2024 & FiOTP‑2023).
Frontier in Metasurfaces & Terahertz Photonics (FiMTP‑2025).
INUP Users’ Meet, IIT Bombay – 10 Aug 2024.

Project Proposals & Initiatives

In collaboration with supervisors and colleagues, I contributed to national research proposals focusing on next‑generation terahertz devices:

Metamaterial‑based terahertz broadband active modulator (ISPEC‑2024) – aimed at developing VO₂‑based phase‑change devices to enhance 6G communication through improved data storage, faster processing and superior signal transmission at THz frequencies.
Investigating THz plasmon dynamics in metasurfaces using FEL techniques (IUAC‑2024) – explores THz‑induced plasmon dynamics using Free Electron Laser methods to study the inverse Faraday effect for polarization control and all‑optical switching.
Machine‑learning‑assisted metamaterials for terahertz photonic applications – focuses on designing and fabricating metamaterials optimized via machine‑learning algorithms for toroidal structures, high‑Q resonances and EIT/BIC‑induced devices for THz photonics.

Featured Research Visuals

Postdoctoral Researcher

Institut national de la recherche scientifique – EMT Centre (2025–present)

Researching tunable metawaveguide architectures for terahertz communication systems and continuing work on active terahertz metamaterials.

Functional metamaterial designs, including broadband lattice‑coupled and toroidal structures.

Schematic of a flexible multi‑stacked metamaterial and fabricated samples used for ultra‑broadband modulation.