This is the MFND-25-0.1, a 25 mm diameter Neutral Density Filter from OptoSigma. The filter is mounted and made of N-BK7 Schott, a high-quality optical glass known for its excellent transmittance and low auto-fluorescence.
The filter is designed for use in the visible spectrum, specifically between 400 and 700nm. It features a thickness of 2mm, providing durability and stability. The filter's neutral density reduces the intensity of light without altering its color composition, making it ideal for various applications such as photography, beam attenuation, and laser applications.
The front and back of the filter are coated with Opt FND-0-1, a reflective neutral density coating. This coating enhances the filter's performance by reducing reflections and increasing transmission, thereby improving the overall quality of the optical system.
The filter's thin lens shape allows for easy integration into various optical systems. It is currently in stock and available for purchase through the provided weblink.