Optics with diamond-like-carbon overcoat (DOC) provide improved optical performance over traditional DLC films and better cleanability than standard PVD coatings

DOC is a coating technology that combines a CVD diamond-like carbon (DLC) film and a physical vapor deposition (PVD) coating in a custom coating chamber. DOC coatings combine the best attributes of DLC and PVD, while minimizing their disadvantages. Traditional PVD IR coatings on windows, lenses and mirrors have good optical properties, but are relatively soft, making them easily scratched during cleaning and handling. DLC coatings are extremely durable but have limited optical performance, bandwidth and higher absorption losses. DOC is not quite as hard or durable as DLC, because it is relatively thin. However, DOC is harder and more durable than standard PVD films. The advantage of DOC is that it is able to be integrated into the optical coating design. This allows coatings to be designed with similar performance to a traditional PVD film, but with much improved durability. Many demanding applications from aerospace to 3D printing have found DOC to be a good solution. In this paper various applications that incorporate DLC or PVD coated optics will be compared with DOC coating alternatives, providing insight for possible solutions using this new technology.