Optical windows are flat plates composed of optically transparent material that allow light to pass through to an optical device. They can also be used to keep a light source safe from the elements. These windows are made to reduce reflection and absorption while increasing transmission over a specific wavelength range. In order to choose an appropriate optical window, one should consider factors like optical surface parameters, material transmission qualities, and the mechanical properties.
There are big optical windows as well as micro windows for nano-sized optical components available in the market and you can also choose from a variety of substrates such as offers a wide variety of optical windows made from materials like N-BK7, Fused Silica, Sapphire, Germanium, Zinc Selenide, Calcium Fluoride, and Magnesium Fluoride etc
When you approach an optical window manufacturer, they will match your exact specifications of an application. You’ll need to keep substrate qualities and optical surface specs in mind as you choose custom optics for your application. Transmission, refractive index, and hardness are all determined by the substrate’s material qualities. For instance, the density of fused silica is 2.202g/cm, and its index of refraction ranges from 1.55 to 1.40.
Optical glasses with a high index of refraction are referred to as “flints,” whereas windows with a low index of refraction are referred to as “crowns.”The Abbe Number, which defines how the refractive index varies with wavelength, is another significant criterion for choosing an optical window. If there is higher the dispersion, the lower will be the abbe number.
It is also important to refine mechanical tolerance or the acceptable limit of size and thickness required for an application. It is specified in inches or mm and typically given a +/- value. Round optical window provides tolerance for diameter. Rectangular/Square window provides tolerance for LxW.
You may need to pay attention to substrate density if your specified application is weight-sensitive. Although optical materials’ refractive index generally rises as density rises, this is not always the case, and the connection is not necessarily linear.
It is also required to determine the size and shape of an optical window. Optical windows can be made in round, square, rectangular and custom shapes. Round windows are often preferred as it provides the best opportunity for obtaining flatness and accuracy in window. You can get windows designed in custom shapes and sizes as per your requirements. When a standard option given in a catalog doesn’t work, COE optics skilled team of professionals craft custom optical windows to meet the requirements of unique projects. These optical windows are customized with following attributes such as
Drill holes and notches
Produce beveled substrates.
Provide custom sizes and shapes.
Design and supply custom coatings
Modify and resurface customer supplied substrates
Most of the good manufacturers have years of experience and expertise, durable coatings and environmental testing capabilities to deliver products meeting most demanding requirements.
