This book offers a comprehensive exploration of the latest advancements in optics, photonics, and advanced materials, addressing critical challenges in the field. It delves into the development of optoelectronic materials for optical limiting and switching applications, breakthroughs in photonic materials and devices, and the integration of photonics for miniaturization and scalability. The role of quantum photonics in next-generation technologies is examined, alongside applications in renewable energy and sustainability.  Key topics include advanced optical sensing and imaging technologies, ultrafast and nonlinear photonics, and the generation and detection of terahertz radiation. The book also provides insights into quantum cascade lasers and the development of fiber lasers and amplifiers. Additionally, it explores nanostructured materials, 2D materials, and smart materials poised to revolutionize future technologies.  This book is an essential resource for scientists, engineers, and researchers in materials science, nuclear physics, and photonics. Compiled from the International Conference on Complex Systems, Advanced Materials, and Photonics (IC-ETCMP-2025), it bridges fundamental concepts with real-world applications, offering a roadmap for future discoveries and innovations. Whether you're a seasoned expert or a curious newcomer, this book provides valuable perspectives on the cutting-edge of scientific research.