Sol–gel coassembly of macroporous cylinders cladded optical fibers

In this paper, we provide a facile way to fabricate a microstructure fiber by coating a standard optical fiber with a silica inverse opal through a sol–gel coassembly method. Polystyrene (PS) colloidal suspension of microspheres and a hydrolyzed silicate precursor were added to the solvent together. With the evaporation of the solvent, the assembly of a PS colloidal template and the infiltration of voids of the spheres with silica gel were executed simultaneously to form a colloidal composite in a single step. After removal of the sacrificial colloidal template, a cylindrical inverse opal (CIO) cladded an optical fiber was obtained. Structural properties characterized by optical and scanning electron microscopy (SEM) and unique transmission spectra with photonic band gaps reveal the high quality of the silica CIOs, which can be used as fiber Bragg grating for optical communications.