Keynote Speakers

Speech Title: A Tale of Force and Light: How Optical Coherence Tomography and Raman Spectroscopy, Combined with Mechanical Testing, Reveal the Dynamic Behavior of Healthy and Diseased Articular Cartilage

Abstract: Articular cartilage achieves long-term load bearing and low-friction joint motion through a finely organised, depth-dependent collagen architecture and tightly regulated biochemical environment. Early disruption of this organisation alters tissue mechanics and molecular behaviour well before gross structural damage, such as osteoarthritis (OA), becomes apparent. However, conventional approaches rely on destructive, end-point analyses that preclude observation of cartilage dynamics under load. Here, we present a multimodal, non-destructive platform combining polarisation-sensitive optical coherence tomography (PS-OCT), Raman spectroscopy, and controlled mechanical compression to interrogate the coupled mechanical, structural, and biochemical response of cartilage in real time.
We have validated a compression–imaging platform, which enables simultaneous acquisition of depth-resolved PS-OCT images, Raman spectra, and force–displacement data during in situ controlled loading. Using bovine cartilage-on-bone samples, the system reproducibly captures classical microanatomical deformation patterns, including chevron-shaped shear deformation and formation of a shear discontinuity, while revealing their temporal evolution during loading. Dynamic birefringence and Raman measurements demonstrate clear distinctions between healthy and artificially damaged cartilage within the first minutes of compression, highlighting the sensitivity of the approach to early mechanical dysfunction.
This platform has been applied to study a range of cartilage tissue, from healthy to those with their surface removed, and cartilage with clear signs of degeneration. The aim is to elucidate mechanisms underlying the initiation of OA. PS-OCT reveals that healthy tissue exhibits a gradual, depth-dependent increase in birefringence with strain that stabilises over time, consistent with controlled collagen reorientation and effective load redistribution. In contrast, damaged and diseased tissues show rapid, irregular birefringence changes, loss of coherent shear boundaries, and reduced lateral load dissipation. Complementary Raman spectroscopy, analysed using two-dimensional correlation spectroscopy, shows coordinated protein-, proteoglycan-, and water-related biochemical responses in healthy cartilage, while diseased tissue exhibits faster, altered biochemical dynamics and disrupted molecular coupling.
Together, these results demonstrate that healthy cartilage uniquely maintains coordinated mechanical, structural, and biochemical dynamics under load. The multimodal platform provides sensitive optical biomarkers of early degeneration and offers a powerful tool for early OA detection, functional tissue assessment, and evaluation of regenerative and therapeutic strategies.

Speech Title: A Photonic, Ultra-fast, and Resource-Efficient Neural Network (PURE-NN)

Abstract: Photonic neural networks (PNNs) show immense potential as a next-generation AI hardware paradigm. Yet, despite rapid hardware innovations, the gap between current PNN systems and practical AI applications remains significant; while effective as standalone components, PNNs are difficult to integrate into modern AI pipelines. To bridge this gap, this work proposes a versatile, digital micro-mirror device (DMD)-based PNN computing unit designed to minimize system complexity and electro-optic conversions. Furthermore, a GPT-inspired image task scheduler is introduced, which drives the PNN as a black-box processor to execute complex tasks.

Speech Title: Imaging Spheroid Morphology and Function by Computationally Augmented Optical Coherence Tomography

Abstract: Spheroids are essential samples for cancer research and regenerative medicine. While recent advancements in cultivation technology have enabled the creation of larger, more complex spheroids that better mimic human physiology, standard imaging modalities cannot adequately assess the three-dimensional morphology and functions of living spheroids. Here, we demonstrate a new label-free, three-dimensional imaging modality: computationally augmented optical coherence tomography (CA-OCT). This modality does not use exogenous agents to highlight spheroid functions; instead, it leverages intrinsic intracellular dynamics to generate three-dimensional functional images. Additionally, several deep-learning models are incorporated to enhance both the imaging speed and quality of CA-OCT. In this talk, the concept and technical details of CA-OCT, as well as its application to spheroid imaging, will be presented.