Patent ID: 11906765
Assignee: nan
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 19:
20. A thin-film interference filter comprising a first thin-film interference multi-layer stack composed of individual thin-film layers arranged in groups to form a plurality of first repeat unit blocks,
wherein the individual thin-film layers of at least two of the repeat unit blocks are arranged in identical orders of refractive indices,
wherein the individual thin-film layers of at least two of the unit blocks are arranged in identical orders of thicknesses,
wherein each of the individual thin-film layers of one unit block has a thickness differing from a respective individual thin-film layer of another unit block by a constant scaling factor such that the one unit block differs from the other unit block by the constant scaling factor,
wherein the thin-film interference filter is flexible enough to be bendable to a radius of curvature of 250 mm or less without permanently damaging, deforming or cracking the thin-film interference filter as a whole, or the thin-film layers in the at least one multi-layer stack, and
wherein the total thickness of the thin-film interference filter is within the range of 0.05 mm to 1 mm.