The choice of glass is a fundamental part in the optical design process. This is especially true for IR and thermal optics materials. In this article, we will review Calcium Fluoride (CaF2), an interesting glass that has a wide range of applications.

If you want to learn more, please visit our website optec.

Before we start, let’s look at the transmission window for CaF2 (Figure 1). As we can see, it has an excellent transmission window with almost 90% transmission from 200 nm all the way to 7 um. What is interesting about this transmission window is that it is pretty consistent, an uncommon feature of optical glass.

If we look at the changes in its refractive index, we will see a variation from 1.475 at 200nm to almost 1.3 at 9 um. The refractive index changes are not linear (Figure 2) and this property is commonly used to enhance CaF2 glass blanks so they can operate more efficiently in a particular window (UV, VIS or IR).

However, working with CaF2 is not easy. CaF2 is usually grown by vacuum in diameters up to 250 mm, which tend to create expensive blanks. As an example, a simple plano-convex CaF2 lens with a focal length of 100 mm and a 2 inch diameter costs around $350, while the same lens made out BK7 costs only a third of that price.

If you are looking for more details, kindly visit Calcium Fluoride Optics.

If an IR application is needed, the crystal can be grown using naturally extracted fluorite but these blanks tend to present absorption bands around 300 nm and have low transmission in the UV region. CaF2 and various combinations of fluoride compounds can be made into synthetic crystals with applications in lasers and special optics for UV and infrared

Calcium Fluoride (NICF Series)

Applications

• Optics for ultraviolet and high-power lasers
• Lens materials and optics for semiconductor and FPD lithography systems
• Lens materials and optics for industrial inspection equipment
• Camera lenses
• Telescope lenses

• *Please contact our sales department for further information on these and other applications

Optical grades and features

Swipe horizontally to view full table.

Transmittance range

• *All data on this page are typical but not guaranteed values.
• *Please ask about different sizes and specifications.

N.B. Export of the products* on this page is controlled under the Japanese Foreign Exchange and Foreign Trade Law. Appropriate export procedure shall be required in case of export from Japan.

Are you interested in learning more about Customized Shaped Spherical Lenses? Contact us today to secure an expert consultation!