Optical monitoring of nonquarterwave layers of dielectric multilayer filters using optical admittance.

The optical monitoring method is described to compensate for the thickness error of nonquarterwave layers of dielectric multilayer filters, using optical admittance during deposition. Stability is confirmed by computer simulation of random thickness error generation in layers. In addition, a band split filter consisting of 61 nonquarterwave and nonperiodic layers is deposited in the proposed method, resulting in high spectral performance, as the design requires.