High performance optical edge and notch filters and methods of making the
same are disclosed. The multi-layer, thin-film optical edge filters have
an edge steepness greater than about 0.8% as measured by dividing (a) the
edge width from the 50% transmission wavelength to the optical density 6
("OD6") wavelength by (b) the 50% transmission wavelength. The optical
edge filters also have an average transmission above about 95%. The notch
filters exhibit a blocking of OD>6, very high transmission (>90%)
outside the notch(es), and a narrow notch bandwidth comparable to that of
holographic notch filters. The methods for making such filters accurately
determine when deposition of each layer of the filter should terminate.