A Review of Optically Transparent Continuous Glass‐Fiber Reinforced Polymeric Composites: Refractive Index Matching, Fabrication, and Applications

Transparent continuous glass fiber‐reinforced polymer composites (tGFRPs) offer high strength, specific stiffness, and optical transmittance, making them promising candidates for applications in architecture, optoelectronic devices, and non‐destructive testing. However, conventional GFRPs suffer from low transparency due to refractive index mismatch and defects such as surface roughness, porosity, and microcracks. To address these issues, refractive index matching and process optimization are key strategies. This review systematically summarizes the optical transmittance models of tGFRPs, along with key strategies for refractive index regulation—such as matrix design, organic doping, curing agent selection, and thermoplastic blending—and process optimization techniques including mold surface refinement and fiber spreading. In addition, recent advances in the application of tGFRPs across typical domains are reviewed. Based on this, current technical challenges are discussed, including the limitations of existing transmittance models, difficulties in achieving full‐spectrum refractive index matching, and the need for efficient and cost‐effective manufacturing techniques. Finally, future development trends are outlined, particularly in the direction of intelligent and multifunctional tGFRPs, aiming to provide theoretical guidance and practical insights for the advancement of high‐performance transparent composites.