Controlled method of manufacture of multiple-notch rugate filters

摘要

An error-compensated process for forming a multiple-notch optical filter which is characterized by a continually and accurately varying periodic profile. The optical medium if formed on a substrate so that the profile of the refractive index is multiply sinusoidally modulated to maintain Bragg's law for each component in the multiple- notch profile. In a preferred embodiment, as the optical medium is coated on the substrate, the depositing film is monitored by optical techniques, and feedback information is provided to a computer driven by a pre- programmed process control algorithm so that real time control of the manufacturing process may be accomplished.