Fig. 4: Modeling results of light propagation in the three TiO2-QOFs.

a Schematic showing TiO2 patchiness on quartz optical fibers (p); b schematic showing average interspace distance between fiber surfaces and TiO2 coating layers (za); c TiO2 coating layer structure parameters (p and za) of the three TiO2-QOFs; and d modeling results of the dissipated radiant energy of evanescent waves (\({E}_{{\mathrm{E}},{{\mathrm{dis}}}}{\prime}\)) and refracted light (\({E}_{{\mathrm{R}},{{\mathrm{dis}}}}{\prime}\)) as well as the returned radiant energy of evanescent waves (EE,return) and the reflected radiant energy from refraction spots (ER,reflect) in the three TiO2-QOFs (conditions: light intensity = 7.02 mW/cm2, wavelength = 365 nm, TiO2 coating length = 6.5 cm, irradiation duration = 4 h).