NE05A In Stock

The Thorlabs NE05A is a mounted absorptive neutral density (ND) filter designed for use in a wide range of optical applications. With a diameter of 25 mm and a SM1-threaded (1.035"-40) lens tube, it is directly compatible with various optomechanical components such as cage systems and lens tubes accessories. The housing of the NE05A is engraved with both the part number and the optical density, making it easily identifiable. The ND filter is constructed from a Schott glass substrate to limit the amount of light in the visible range between 400-650 nm. This glass has been chosen due to its ability to absorb light evenly across the spectrum. This provides a more stable and predictable performance compared to reflective metallic filters. The NE05A has an optical density of 0.5 (32%), which indicates the attenuation factor provided by the filter and how much it reduces the optical power of an incident beam. The diameter tolerance of the NE05A is +0.0 / -0.25 mm, and it has a clear aperture of >Ø22.5 mm. 

While the NE05A is durable and reliable, it is still a delicate optical component that requires proper handling and cleaning to maintain its performance and extend it’s lifetime. Contaminants such as dust, water, and skin oils can increase scatter and absorb incident radiation, causing hot spots on the optical surface and permanent damage. Always unpack or open optics in a clean, temperature-controlled environment and avoid handling the filter with bare hands. If dust or other contaminants are present, they should be removed with a canister of inert dusting gas or a blower bulb. Do not use your mouth to blow on the surface of the filter as saliva droplets can cause damage.

To further protect the NE05A, it should be stored in a specific optic storage box, wrapped in lens tissue and kept in a low humidity, low contaminant, and temperature-controlled environment. It is important to note that the NE05A is not designed for use as laser safety equipment. By following these guidelines, you can ensure that your NE05A ND filter has optimal performance and longevity.