Executing highly optimized sputtered interference-coating designs for colorimetry and light balance filters using broadband monitoring

The theoretical transmittance spectra of a highly optimized interference coating design for a tristimulus filter can mimic a target spectrum with near-zero spectral mismatch. But to make such a filter in practice requires a tightly controlled deposition process that employs broadband in situ spectral monitoring which provides continuous feedback and allows subsequent layer correction. We demonstrate spectral matching (using the integral parameter f1') <1.5% and model the effects of spectral mismatch on color measurement accuracy. Optical modeling showing the sensitivity of the filter response to variations in angle of incidence and for determining how to deal with stray light are also demonstrated.