Optical Properties Control of Hollow Core Microstructured Optical Fibers by Layer‐by‐Layer Assembled Quantum Dots and Annealing

Abstract Hollow core microstructured optical fibers (HC‐MOFs) have attracted considerable attention in photonics, particularly for their potential in sensing applications in biology and medicine. This work presents a novel approach to modifying HC‐MOF inner walls using quantum dots (QDs) and HC‐MOF facets via hybrid membranes. These modifications are achieved through layer‐by‐layer (LbL) assembly, resulting in a reduced light transmission and a spectral red shift. Subsequent annealing restores transmission and induces a spectral blue shift. A similar effect is observed under low‐pressure annealing when a mirror is installed on the facet of the modified fibers. An optimal method is demonstrated for these modifications and their impact is analyzed on HC‐MOF transmission spectra and QDs photoluminescence. These findings highlight the practical approach to these modifications, paving the way for advanced HC‐MOF‐based sensors and multimodal probes in biomedical applications.