Welcome to my webpage. I am a Professor of Photonics at the Indian Institute of Technology Delhi, working in the areas of guided-wave photonics, non-Hermitian optics, and advanced optical sensing. My research focuses on optical waveguide gratings-including fiber Bragg gratings (FBGs), long-period gratings (LPGs), interferometric and multimode photonic structures—as well as emerging concepts such as photonic time crystals and exceptional-point-enhanced sensing.

A major theme of our work is the development of high-performance and temperature-insensitive photonic sensors through mode engineering, dispersion control, multimodal interference, and machine-learning-assisted signal demodulation. More recently, we have been exploring non-Hermitian photonic dynamics and reciprocal exceptional points for enhanced optical sensing and signal transduction.

Our group has developed photonic sensing platforms for biochemical and environmental monitoring, including detection of E. coli bacteria, cyanobacteria, and microcystin-LR molecules in water. This work has resulted in several important discoveries, multiple patents, and the development of the world’s first inherently temperature-insensitive fiber-optic sensor for accurate E. coli detection under large temperature fluctuations.

We have also made foundational contributions to guided-wave photonics through the discovery and physical interpretation of critical-wavelength phenomena in modal-interference-based fiber sensors, establishing new paradigms for sensitivity engineering in optical sensing.

Broadly, our interests span Fiber Bragg Gratings (FBGs), Long-Period Gratings (LPGs), directional couplers, interferometric sensors, plasmonics, metamaterials, photonic integrated systems, and intelligent data-driven photonic technologies for next-generation sensing applications.

You may contact me at smt@opc.iitd.ac.in