Choices of Crystal Orientation for Sapphire Window:
Crystal orientation determines the characteristics of sapphire windows. The choice of crystal orientations depends on many factors e.g. birefringence, thermal expansion, lattice constant and other crystal orientation dependent physical properties.
For example, C-plane sapphire is slightly birefringent. Sometimes specifized as ‘zero degree’, or ‘c-cut’. In a window, the optical axis of sapphire should be perpendicular to the plane of the window. Most sapphire windows require low birefringence, so C-plane is typical material for Sapphire windows.
If unspecified, Random should be the default crystal choice for sapphire windows. The window is fabricated without concern about crystalline orientation, called ‘random’ cut. But need to note that this is nearly 60° to the optic axis as this is the ‘softest’ direction for the saw.
Sapphire Window Polishing:
Due to its hardness and high mechanical strength, the polishing of sapphire window is difficult and slow. To develop a process for the production of sapphire windows with optical flatness, low scatter surface finish and without surface and subsurface damage is very challenge.
Our super polishing processes enable us to polish sapphire windows with low roughness, high surface quality and surface accuracy.
Sapphire Windows Coating:
The applications of sapphire windows rang from Defense and Aerospace to Sensors and Instrumentation to Medical Devices.
Sapphire windows need to work under extreme operating conditions and demonstrate superior performance. So the coating need to withstand harsh environmental conditions, and the coating designs are multispectral to take advantage of the wide wavelength transmission property of sapphire.
We have diverse experience to guarantee thin film spectral uniformity over the clear aperture.
We offer antireflective and dielectric coatings for UV, VIS, MIR, and multispectral applications.