Manufacturing Metal Mirror for Industrial Applications

Metal mirror optics offer high reflectivity and are highly desirable for use in illumination and imaging systems, telescopes, LIDAR applications, HUD systems, and other precision optical instrumentation. At CMM Optic, we have developed our processes to provide you with industry-leading diamond-turned mirrors with a sharp focus on the details. In this article, we are going to focus on metal mirrors regarding the manufacturing first surface mirrors. Occasionally, these are referred to as “front surface mirrors” or FSM.

Getting rid of the ghost. First surface mirrors, created with metal coatings on glass, eliminate the ghost image from the first layer by coating the front surface, rather than the back of the glass optic. The elimination of ghosting is desirable for applications where the image or light must be manipulated beyond the original reflection. Second surface mirrors are coated behind the front surface, which creates the opportunity for the ghosting to occur in imaging.

CMM Optic avoids this ghosting issue by creating metal mirrors made with stringent tolerances which offer high reflectivity prior to an additional reflective coating application. Creating a polished metal mirror is advantageous where thermal expansion may be an issue, or when other environmental factors are a concern, such as oxidation or high humidity. The need for field replacements is diminished when using a metal substrate instead of a coated glass mirror in many applications.

High tolerances are our bread and butter. Our manufacturing process of diamond-turning optical mirrors meets exceptionally high tolerances. Tolerances are measured in angstroms for ideal surface quality, and surface roughness. We create parabolic mirrors, polynomial mirrors, Plano, complex cylinders, and aspheres that are designed for beam delivery solutions in the visible and IR wavelengths.

If the final application requires enhanced performance, a metal coating may be applied. Coatings applied to a glass surface can be fragile and prone to scratching. A mirror created from precisely milled aluminum tends to offer a more stable surface area than glass. The mirror surface is created during the actual shaping process, eliminating the need for post polishing steps in most applications.

Our broad machining capabilities, including the use of our DMG-Mori CTX, enable us with the ability to manufacture mirrors directly from blank stock to create complex shapes. In addition, our state-of-the-art metrology laboratory verifies and measures tolerances at the sub-micron level.

Metal mirror applications. One widespread use of a curved metal mirror is as part of a reflector sight system. An older technology, but still used today in handgun sights and aircraft gun sights, a reflector sight uses an image-forming curved mirror in conjunction with a reflective overlay image at the focal point to create a virtual image. Another common use of the reflector sight system is within a reflective optical telescope, as there are no refractive elements required. As these systems must perform in the atmosphere, a protective coating is recommended to seal out corrosive elements. Aluminum mirrors typically have a layer of silicon dioxide, or magnesium fluoride added to keep the surface areas pristine.

CMM Optic has received ISO 9001:2015 and AS9100D certification and is ITAR Compliant.

Whatever your optical mirror needs may be, our industry-leading capabilities and processes offer increased yields, on-time delivery, and minimized production time.

We are Redefining What is Possible in optical metal mirror production. Please let us know how we can help with your next project. Our highly experienced staff is ready to support you all the way throughout the entire process.