Home / Custom / Optical Components / Optical Mirror / Dielectric Mirror Dielectric mirror, also known as Bragg mirror, is a type of mirror composed of multiple thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material. By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified reflectivity at different wavelengths of light.
These are its core advantages. At specific wavelengths (e.g., 532 nm, 1064 nm, 1550 nm), its reflectivity can easily exceed 99.9%, with absorption loss of less than 0.01%.
Due to its extremely low absorption, it generates almost no heat, thus capable of withstanding extremely high laser power densities. This makes it a core component for beam steering and focusing in high-power laser cutting, welding, and marking systems.
By adjusting the thickness and material of the coating, dielectric mirrors can be precisely designed to operate for specific wavelengths (narrowband) or specific bands (broadband).
It is sensitive to the polarization state of light, especially under non-normal incidence. The reflectivity of S-rays and P-rays differs, a point that requires special attention in precision optical design.
| Structure | Flat, Sphere, Cylinder, or customized shape |
|---|---|
| Substrate | Fused silica/ Silica/ BK7 Glass |
| Dimension | 2mm~100mm |
| Clear aperture | >90% of dimension |
| Surface quality | 40/20, 20/10 Scratch-Dig |
| Surface Irregularity | λ/2~λ/10 @632.nm |
| Thickness | 1mm~20mm |
| Coating | UV/ VIS dielectric coating |