Additive manufacturing of light-emitting active 3D optical structures

 Additive manufacturing of arbitrarily shaped, light-emitting 3D structures is a pivotal innovation for controlling the beam propagation direction, angular distribution, emission point, and wavelength of active light sources. These light sources, which include microscale lasers, light-emitting diodes, quantum dots (QDs), and other emerging materials, are crucial for applications such as 3D cellular imaging, biomedical endoscopy, linear and non-linear imaging spectroscopy, photonic circuit integration, optical computing, and high-precision metrology in semiconductor and flat-panel display inspection. To meet the diverse requirements of these applications, various light-emitting materials, such as fluorescent dyes, up-conversion nanoparticles, QDs, and non-linear optical media, have been incorporated into additive manufacturing techniques. Over the past decade, several additive manufacturing methods have been adapted for fabricating active 3D optical structures, including inkjet printing of functional inks, fused deposition modeling of light-emitting filaments, selective sintering of active material powders, and two-photon polymerization of photonic polymers. These methodologies offer unprecedented versatility in designing and constructing complex optical structures with integrated light-emitting properties. The advent of such novel 3D-printed active optical systems promises to revolutionize fields ranging from on-chip photonics to advanced spectroscopy and precise optical measurement techniques, ultimately enabling new frontiers in photonic technologies and their applications.