Functionalized Micro Structured Optical Fibers and Devices for Sensing Applications: A Review

With the development of the volume of information exchange and perception increases, the demands for intelligent, miniaturized, and integrated optical devices for information acquisition are also increasing. In the meanwhile, different from the traditional optical fibers as optical nerves, microstructured optical fibers (MOFs) give new vitality to optical functional devices because of its flexible structure and controllable optical properties. Due to the diversified air-hole structure, various functional materials can be introduced into the cladding of MOF to realize optical signal shaping, external mechanical field or biochemical sensing in different environments. Resides, various modifiable structural properties of MOF are also important in functional applications. Recently, several notable breakthroughs and progresses on promoting the modification methods have been achieved, enabling MOFs with specific functionality and engaging significant applications. In this article, we briefly summarize different kinds of MOFs, and review the optical characterization and implementation of MOFs based on optical functional devices, crossed by our developments of the metal and twist modification studies of MOF for sensing fields. Moreover, the challenges, prospects and promising opportunities of future functional MOFs for sensing applications are also presented.