Optical Glass substrates are mounted on rotation disks which we will refer to as "planets". The proper term for this type of system is a "Planetary System", as in it functions just like our own planetary system. Each planet is rotating while the planetary system is rotating inside the chamber. This is not true for sputtering or CVD. Each of these processes has its own unique way of depositing material on to a substrate.

At the base of the vacuum chamber there is a rotating mullet crucible where the dielectric materials are loaded. Below the crucible is the source, the electron beam, used to heat and evaporate the dielectrics. You can control the motion of the E-Beam with a sweep controller. 

In a thermal vacuum environment the materials become an inherent part of the substrate. This process is achieved without opening the chamber. Monitoring is done by passing lightwaves to a blank monitor substrate. The reflected light is passed through a momochrometer and onto a detector.

As the thickness of the deposited material changes, the light intensity of the signal oscillates in a simulated sine wave. This is known as optical monitoring and by counting a specified number of peaks and valleys the coating technician can accurately deposit a layer of materials to within ± 3nm thick. With thermal and vacuum conditions controlled we are able to produce an extremely durable coating that resists heat, thermal shock and abrasion.

Production and control is a major factor with regard to the quality of the dichroic color filter you are purchasing. First you must have a design team capable of producing a product to meet your application.