A narrow-band transmission filter based on one-dimensional photonic crystals with SiO2/titaniumdioxide(TiO2) layers is grown by sol-gel spin-coating processing. The structural and optical properties of fabricated samples are characterized by an atomic force microscope, scanning electron microscope, and UV-visible spectroscopy. Specific wavelength transmission and bandgap in the optical filter with and without a defect layer have been investigated by engineering the layer thickness and defect layer material. For three fabricated optical filters, it is found that the maximum transmission for the TiO2 and InP defect layers reaches 58.09% and 42.21%, respectively. The layer thickness is fixed just by tuning the rotational speed of the spin-coater.