Fabrication and Characterization of a Colloidal Crystal Cladding Micro-Fiber

A method of fabricating colloidal crystal cladding micro-fiber was demonstrated. Polystyrene microspheres were coated around the surface of a micro-fiber through isothermal heating evaporation induced self-assembly, yielding continuous, uniform, and well-ordered colloidal crystal cladding. The colloidal crystal cladding has face-centered cubic (FCC) structure, with the [111] crystallographic direction normal to the surface of micro-fiber. The transmission peak of the colloidal crystal cladding micro-fiber locates at 680 nm, arising from the Bragg reflection of an FCC structure at the [111] direction. The modulation amplitude is similar to 20 dB. This micro-fiber with the 3-D photonic crystal structure possesses potentialities in the applications of micro-fiber filters or sensors.