An optical filter includes a carrier layer made of a first material. A periodic grating of posts is disposed on the carrier layer in a periodic pattern configured by characteristic dimensions. The posts are made of a second material. A layer made of a third material encompasses the periodic grating of posts and covers the carrier layer. The third material has a refractive index that is different from a refractive index of the second material. Characteristic dimensions of the periodic grating of posts are smaller than an interfering wavelength and are configured to selectively reflect light at the interfering wavelength on the periodic grating of posts.