Pressure and temperature controlled self-assembly of high-quality colloidal crystal films on optical fibers

High-quality annular colloidal multilayer films coated on an optical fiber were fabricated from aqueous solutions by the modified vertical deposition method with controllable pressure and temperature. The resulting cylindrical annulus was characterized by the scanning electron microscopy (SEM), and the SEM images illustrated the [111]-like plane of face-centered-cubic (fcc) structures parallel to the surface of the optical fiber. Transmission spectra demonstrated deep photonic band gap (PBG) of up to 76% and steep photonic band edge (PBE) of up to 5.2%/nm, as well as the excellent cylindrical symmetry was affirmed with off-axis incidence light. With the angles of out-of-plane incidence increasing from 0 to 60°, the peak positions and transmittance decreased gradually which agreed well with the Bragg formula.