FND-15C02-1 15 mm Dia. Unmounted N-BK7 Visible Reflective Neutral Density Filter; t=2mm 400-700nm

The FND-15C02-1 is a high-quality Neutral Density Filter, unmounted and 15 mm in diameter, manufactured by OptoSigma. This filter is designed for use in the visible light spectrum, specifically between 400 and 700 nanometers, making it suitable for a wide range of optical applications.

The filter is made from N-BK7, a type of borosilicate glass manufactured by Schott AG, which is known for its excellent optical properties. The N-BK7 material ensures high transmission and low absorption across the visible spectrum, making it an ideal choice for applications requiring high-quality, neutral density filtration.

The filter features a thickness of 2mm, which is designed to provide a balance between mechanical strength and optical performance. The thin design helps to minimize unwanted optical effects such as ghosting and flaring, which can occur when light passes through multiple surfaces.

The filter is coated with OptoSigma's proprietary FND-1 coating on both the front and back surfaces. This coating is designed to provide high reflectivity in the visible spectrum, making it ideal for applications where reflective neutral density filtration is required. The coating also provides excellent durability and resistance to environmental factors, ensuring the filter maintains its performance over time.

The filter has a shape described as a Thin Lens, which is a type of optical element that focuses light. This shape is designed to provide optimal optical performance, minimizing distortions and aberrations.