My research focuses on advancing next-generation photonic technologies through the integration of advanced fabrication, functional materials, and nonlinear optics. The primary focus is on femtosecond laser-based direct writing, including 3D laser direct writing of high resolution microstructures via two-photon polymerization. This approach supports the realization of free-form optical waveguides and lab-on-fibre-tip devices, paving the way for compact, highly integrated photonic systems. Building on this fabrication capability, the research also investigates optical phase change materials, particularly the GST family, with emphasis on their intermediate states. These states exhibit tunable optical and nonlinear properties, offering new opportunities for light guiding, optical switching, and reconfigurable photonic devices. In parallel, my work also explores nonlinear optical phenomena, especially spontaneous parametric down-conversion, for the development of entangled photon sources. These sources are essential for emerging applications in quantum communication and photonic information processing. Together, these efforts aim to bridge fabrication, materials, and device physics, contributing to scalable, adaptive, and multifunctional photonic platforms for both classical and quantum technologies.