Addressing Biomedical Challenges with Novel Nanophotonic Probes

From the molecular to the macro scale, the interplay of order and disorder in biological matter is intimately linked to the onset and progression of leading global health challenges such as heart disease, Alzheimer’s disease and cancer. Anisotropic matter, ubiquitous in biological systems such as amino acids and ordered structural proteins, interacts selectively with light, thus presenting a rich palette of opportunities to non-invasively probe and visualize disease. However, naturally occurring anisotropic light–matter interactions, where light is an electromagnetic plane wave, are inherently weak, lying below thresholds relevant for biomedical applications. In the Poulikakos Lab, we address these challenges by leveraging the immense potential of nanophotonic materials to illuminate structural changes in biological matter for clinically-relevant disease diagnosis, assessment and quantitative optical visualization.

Functional Metasurfaces for Rationally-Designed Light–Matter Interactions

Metasurfaces are artificially engineered, two-dimensional systems which can alter electromagnetic fields in a manner unforeseen by nature. Such phenomena include negative refraction, electromagnetic cloaking and optical holography. In addition, these surfaces can be designed to replicate or enhance naturally occurring electromagnetic phenomena in a two-dimensional on-chip environment, including flat optical components such as metalenses and optically-thin waveplates. The key to metasurface design lies in the periodic arrangement of optical elements, known as meta-atoms, which are smaller than the wavelength of light. Meta-atom resonant properties can be controlled by their geometry and material composition. For example, meta-atoms exhibiting material or structural anisotropy enable a myriad of tailored interactions with polarized light. Their small scale enables the confinement of electromagnetic near fields to sub-wavelength dimensions and their two-dimensional periodic arrangement gives rise to strong collective resonances. In the Poulikakos Lab, we develop complex, on-chip optics with functional metasurfaces, thus opening new avenues to address technological challenges and create miniaturized, all-optical device architectures, including diagnostic applications with facile clinical implementation.