Two-dimensional (2D) materials -such as graphene and monolayers of transition metal dichalcogenides (TMDs)- exhibit exceptional light-matter interactions due to their reduced dimensionality and unique crystal symmetries. While only a few dozen layered compounds have been experimentally synthesized, theoretical predictions suggest that over 5,000 stable 2D materials await discovery, with properties ranging from semiconducting to magnetic and topological. By stacking or twisting different layers, we can form van der Waals heterostructures and moiré patterns that offer new ways to control their behavior. This tunability has led to the rapidly growing field of twistronics.

In this talk, I will present insights from our recent optical studies of atomically thin semiconductors, focusing on how excitons -bound electron-hole pairs created after light absorption- govern many of their optical properties. I will discuss how the energies of these excitonic states can be tuned using electric and magnetic fields or by adjusting the twist angle between layers. I will also highlight strategies for confining and guiding excitons, which could support future excitonic circuits for information processing. Finally, I will briefly show how carrier density, mechanical strain, alloying, and coupling to photonic nanoantennas provide additional routes for tailoring light-matter interactions in these materials.

Medical optical imaging is entering a transformative phase, with emerging techniques extending surgical visualization far beyond conventional white light. My work on integrating spectral and fluorescence molecular information into surgical microscopes and endoscopes aims to support more detailed assessment of tissue classification, function, and pathology. I will present recent developments in illumination and imaging optics, together with complementary image-processing advances, that collectively point toward a new generation of surgical imaging systems — systems designed to enable more precise and better-informed interventions.

Developing next-generation sensors requires materials with tailored optoelectronic properties capable of detecting subtle molecular changes. Achieving this performance requires going beyond intrinsic material characteristics through precise materials engineering. This seminar presents the systematic engineering of metal halide perovskites, utilizing them as a unique tool to address these challenges.

I will describe our multi-level approach using room-temperature synthesis methods: compositional control through ion exchange, morphological optimization, surface functionalization for environmental stability, and photo-induced modification using ultrafast lasers. These strategies enable precise tailoring of electronic, structural, and surface properties relevant to sensing performance.

I will discuss how these specific material features determine their application in gas-phase detection targeting inorganic gases and Volatile Organic Compounds (VOCs) for environmental monitoring, breath diagnostics, and food safety, as well as liquid-phase sensing for aqueous contaminants. Both lead-based and lead-free architectures will be examined, addressing the balance between performance and sustainability.

Throughout the seminar, I will emphasize structure-property-performance correlations, demonstrating how systematic materials design optimizes key sensor metrics: sensitivity, selectivity, stability, and response speed. The work illustrates how fundamental materials science translates into practical devices, while introducing a multimodal sensing approach for comprehensive and selective molecular recognition.

In this seminar, I will present two complementary research directions that my group at DTU has developed to extend high-impact photonic sensing applications across diverse domains - from environmental monitoring and bioimaging to the central nervous system.

The first part focuses on the development of laser sources enabled by strong light–gas interactions in hollow-core fibers, generating light pulses from the deep-UV to the mid-infrared. I will show how these lasers can be uniquely combined with photoacoustics for high-resolution environmental sensing and advanced (bio)imaging. The second part will present results using soft polymer materials to create flexible, fiber-based bidirectional neural interfaces that integrate multiple functionalities and embedded local sensing elements through laser-structured patterns.