NE02B-A Dia. 25 mm AR-Coated Neutral Density Filter; 350-700nm; OD 0.2 AR 350-700nm

The NE02B-A is a Neutral Density Filter with a diameter of 25 mm, manufactured by Thorlabs. This filter is designed for use within the wavelength range of 350-700nm, making it suitable for a wide range of optical applications. The filter has a thickness of 1.4mm, which is relatively thin, reducing the likelihood of introducing optical aberrations.

The NE02B-A filter features Anti-Reflection (AR) coatings on both the front and back surfaces. These coatings are specifically designed for the 350-700nm wavelength range, further enhancing the filter's performance within this spectrum. The AR coatings help to minimize surface reflections, thereby improving transmission and reducing the likelihood of unwanted ghosting or flare effects.

The filter's Neutral Density (ND) property is characterized by an Optical Density (OD) of 0.2. This means that the filter reduces the intensity of the incident light by a factor of 1.26, or approximately 26%. This can be useful in a variety of applications where it is necessary to control the intensity of light without significantly altering its color balance.

The filter's shape is described as a Thin Lens, which suggests that it has been designed to minimize optical aberrations and distortions. This is particularly important in high-precision optical systems where even minor aberrations can significantly degrade performance.