When we talk about risk mitigation related to optics, a “risk” is anything in the product development process that can have an impact on cost, schedule, and, of course, technical performance. One such risk is coating and a good place to begin your evaluation of the risk on performance is by vetting the coating supplier. Here are some useful questions to ask.
1. What is your approach to vertical integration?
When considering coating, vertical integration negates the time and expense of transporting optics to a separate coating supplier and back again. It also counteracts the risk of trying to apportion blame if an optic fails. Was it poorly fabricated, or did it fail because of distortion due to coating stress? You need to know you can rely on a single supplier that possesses the technical expertise to select the most appropriate substrate material. The supplier should be able to then fabricate, coat, assemble, and perform testing and verification via sophisticated metrology tools on their unique optics. Facilities should include Class 1000 and Class 100 cleanrooms to ensure a clean substrate, and a supplier’s packaging capabilities should be suitable for protection of delicate coated optics.