An exemplary optical filter includes a substrate, a plurality of contiguous identical lower filter cavities formed on the substrate, and a plurality of contiguous upper filter cavities formed on the lower filter cavities. Each of the lower filter cavities includes two high refractive index layers and one low refractive index layer sandwiched between the high refractive index layers. Each of the upper filter cavities includes two low refractive index layers and one high refractive index layer sandwiched between the low refractive index layers. The plurality of upper filter cavities includes a first filter cavity, a plurality of second filter cavities, a third filter cavity, and a plurality of fourth filter cavities.