Applications of UV Lenses

UV lenses may be used for focusing ultraviolet light sources, for polychromatic illumination in fluorescence applications, for microlithography, spectroscopy, and  laser fusion projects. From military and defense to industrial quality control and forensics, UV optics is a robust and rapidly growing field. 

Sometimes the term “UV lenses” is also used to refer to lenses that are UV-coated to protect the eye from the sun’s harmful rays. Macular degeneration is just one of many eye problems that can occur if the eye is subjected to UV rays from light sources like the sun. However, UV protection coatings can ensure that you are fully protecting your eyes, even when the ultraviolet index is high. 

Special Considerations for UV Lenses

While UV lenses function similarly to other lenses and are used in similar applications, there are important considerations when working with UV optics. Scattering, dispersion effects, and laser damage/degradation are crucial issues to consider when designing a UV setup.

Scattering effects occur across the entire spectrum, but encountering any inhomogeneities or scratches on a lens. To minimize scattering, ensure that any UV lens has minimal parasitic birefringence, a homogeneous refractive index, and a highly polished surface.  

Dispersion effects also vary depending on the spectral region, with many substrates exhibiting stronger chromatic dispersion in the UV range compared to visible (Vis) and infrared (IR) light. Achromatic optics can mitigate this issue when necessary.

Laser damage and degradation can be a concern, as the optical damage threshold of substrates is often lower in the UV spectral range than for longer wavelengths. This is due to two-photon absorption, which can be sufficient to bridge the band gap. To prevent laser damage and degradation, ensure your UV lens is designed for UV light and lasers, and avoid exposing it to vapors from lubrication oils within intense ultraviolet beams.