Photonic crystal optical filter, reflective color filter, display apparatus using the reflective color filter, and method of manufacturing the reflective color filter

A reflective color filter comprising:

• a transparent substrate;
• a barrier layer on the transparent substrate and having a plurality of pixel areas, the barrier layer entirely covering a surface of the transparent substrate;
• and
• a plurality of photonic crystal units on the plurality of pixel areas, each photonic crystal unit having a first material periodically arranged within a second material and an optical cut-off layer on the first material, the first material being formed into island-shaped patterns, the second material being formed to entirely cover the first material and the optical cut-off layer and to entirely fill spaces between the island-shaped patterns of the first material, a refractive index of the first material being higher than a refractive index of the second material, the photonic crystal unit configured to reflect light having a wavelength band corresponding to a photonic band gap.