AND-40S-70 40 x 40 mm Optical Glass Unmounted Visible Absorptive Neutral Density Filter 400-700nm

The AND-40S-70 is a high-quality Neutral Density Filter, offered by the renowned optical components manufacturer, OptoSigma. This filter is designed to minimize the intensity of light passing through the optical path without altering its color composition, making it an essential component in various optical systems.

The filter boasts a base shape of 40 x 40 mm, providing a generous aperture for a wide range of applications. It is made from UVFS MAL-1965 optical glass, a material known for its excellent optical properties and durability. The filter's thickness is 2 mm, ensuring rigidity and resistance to mechanical stress.

The AND-40S-70 features absorptive coatings on both the front and back surfaces, identified as 'opt and-70'. These coatings are specifically designed to absorb a significant portion of the light, thereby reducing its intensity. The coating's wavelength of 550 nm indicates its optimal performance in the green region of the visible spectrum. However, due to the nature of absorptive filters, it still provides a reasonable level of attenuation across the entire visible spectrum, from 400 to 700 nm.

The filter's geometry is that of a Thin Lens, which implies that it has been designed to minimize optical aberrations and distortions. This feature is crucial in applications where high image quality is paramount, such as in imaging, metrology, and beam shaping.