The optical windows available from AMS Technologies are made from a broad range of materials like optical glass, quartz glass, Borosilicate glass and colour-filter glass, as well as crystals like Si, Ge, BaF2, LiF, MgF2, CaF2, CdTe, KBr, GaAs, ZnS, ZnSe, Sapphire and others. For infrared (IR) applications, we offer an especially broad range of optical windows, either uncoated or AR-coated.
In addition to parallel optical windows where a very high degree of parallelism is desired (e.g. below 3 arcmin), wedged optical windows or optical wedges are also available, featuring well defined angles between the upper and lower window surface. Typical angle values for this kind of optical windows are 0.5° (30 arcmin) or 3°.
Way beyond the range of standard products, our suppliers design and produce customized optical windows on request. Please contact the AMS Technologies optical solutions experts to discuss your customized optical window solution that exactly matches your application’s requirements.
Precision optics of this kind, manufactured and coated to very specific and demanding tolerances, is in great demand by our customers. Other available components that can be realized include optical mirrors, spherical lenses and molded glass aspheric lenses, cylindrical lenses, prisms or optical filters – all featuring high precision, lowest tolerances (dimensional and angular) and special coatings for exotic wavelengths, even into the UV spectral range.
Beyond these optical components, AMS Technologies carries a broad range of complementary products such as optical mounts, rotary and translation stages, optical tables, breadboards and platforms, lasers and light sources as well as a broad range of optical test and measurement equipment.
An optical window is used to separate two environments of different pressure, temperature, etc., while allowing light within a specified wavelength range (depending on material and coating) to pass between the two environments.
How to Select Your Optical Window
Flatness defines the value of the deviation of a window from a perfectly flat surface. Flatness is usually measured by bringing the surface of the window into contact with a very flat reference surface (optical flat). The curvature of the resulting fringes is a measure of flatness and is expressed in fractions of the wavelength of the light emitted by the test light source.
The surface finish or surface quality of an optical window is a value that evaluates surface irregularities as they may occur in the manufacturing process. Such irregularities can have a very small effect on the window’s scattering and optical transparency and are of particularly important in demanding applications with high optical power. Surface finish is most often defined by the "scratch-dig" specification, which gives the visual appearance of the width of a scratch and the diameter of a maximum allowable dig in a combination of two dimensionless numbers.
For an optical window of any given material, an angle of incidence exists for which the angle between the reflected and the transmitted light is 90° - known as the Brewster Angle and of particular interest because at this angle the reflected light is plane (s-) polarized and the refracted light is partially polarized. A stack of windows placed at the Brewster angle will reduce the s-polarized component of the incident light until it becomes insignificant.
Angle of Total Internal Reflection:
Some of the light travelling within a high refractive index material will reflect off the boundary with a material of lower refractive index. In this case there exists an angle of incidence where all of the light incident on the boundary will be reflected and none is transmitted. This is known as the window’s angle of total internal reflection.