Deposition error compensation for optical multilayer coatings. II. Experimental results-sputtering system.

A fully automated magnetron-sputtering system for the deposition of complicated optical multilayer structures is described. The process control includes the real-time determination of the deposited layer thicknesses and adjustment of the remaining layer thicknesses to reoptimize the final performance of the multilayer system. With this deposition system it should be possible to produce almost any all-dielectric filter that can be designed, subject only to limitations imposed by time, cost, and mechanical stability of the coatings. To demonstrate the performance of the deposition system, five complex multilayer systems were fabricated. The theoretical and measured spectral transmittance curves of these multilayer systems closely agree with one another over broad spectral regions. The equipment is capable of unattended operation over periods of 24 h or more.