OPTICAL INTERFERENCE FILTER

In some implementations, an optical interference filter includes a substrate; and a set of layers that are disposed on the substrate, wherein the set of layers includes: a first subset of layers; and a second subset of layers; wherein: each of the first subset of layers includes an aluminum nitride (AlN) material, a stress of each of the first subset of layers is between −1000 and 800 megapascals, the first subset of layers has a first refractive index with a first value, each of the second subset of layers includes at least one other material, the second subset of layers has a second refractive index with a second value that is different than the first value, and the optical interference filter has an effective refractive index greater than or equal to 95% of a highest value of the first value and the second value.