About us
We are a theoretical research group at the School of Electrical and Electronic Engineering and the Institute for Digital Molecular Analytics and Science at Nanyang Technological University, Singapore. The group is lead by Assistant Professor Matthew R. Foreman.
Our research focuses on optical and plasmonic sensing, polarisation sensitive imaging, disordered media and electromagnetic theory. More information on some of our past and present projects can be found by visiting our Research pages.
Recent news
New arXiv preprint
11 Aug 2025: We have a new preprint out on arXiv! Our paper, "Generalized Wigner-Smith theory for perturbations at exceptional and diabolic point degeneracies," introduces a new residue-based perturbation theory to understand and predict how non-Hermitian systems respond to external changes. We believe this offers a powerful framework for precision tuning and inverse design.
New PhD Student - Duong Le Dang
4 Aug 2025: As we start a new academic year OTG is joined by a new member, Duo. Although new to his PhD, Duo is not new to the group having previously worked with us as a Global Connect+ Fellow. He has however now graduated from Hanoi University of Science and Technology with his BSc in Electronic and Telecommunication Engineering and come back to Singapore, where his project will be looking at modelling and informatic optimisation of optical imaging and sensing devices.
Paper published in Newton
URECA Poster Competition Winner
24 Jun 2025: Congratulations to one of our URECA students, Mai Anh Le Thuy, who has been named as one of the URECA poster competition winners. This is testament to all of her hard work throughout the last two semesters and is well deserved! You can see the poster here. Well done!
ICMVA 25
13 Jun 2025: This week Ganesh is at the International Conference on Machine Vision and Applications (ICMVA 25) in Melbourne, Australia to present on some recent results on image reconstruction in lensless imaging using a genetic programming approach. Check out his talk!
Recent publications
Abstract : Perturbing resonant systems causes shifts in their associated scattering poles in the complex plane. In a previous study [arXiv: 2408.11360], we demonstrated that these shifts can be calculated numerically by analyzing the residue of a generalized Wigner-Smith operator associated with the perturbation parameter. In this work, we extend this approach by connecting the Wigner-Smith formalism with results from standard electromagnetic perturbation theory applicable to open systems with resonances of arbitrary quality factors. We further demonstrate the utility of the method through several numerical examples, including the inverse design of a multi-layered nanoresonator sensor and an analysis of the enhanced sensitivity of scattering zeros to perturbations.
Abstract : Resonances of open non-Hermitian systems are associated with the poles of the system scattering matrix. Perturbations of the system cause these poles to shift in the complex frequency plane. In this work, we introduce a novel method for calculating shifts in scattering matrix poles using generalized Wigner-Smith operators. We link our method to traditional cavity perturbation theory and validate its effectiveness through application to complex photonic networks. Our findings underscore the versatility of generalized Wigner-Smith operators for analyzing a broad spectrum of resonant systems and provides new insight into resonant properties of non-Hermitian systems.
Funding
Our research is supported by generous funding from:
