ND240B 50 mm x 50 mm; Unmounted Reflective ND Filter; Optical Density 4.0

The ND240B is a Neutral Density Filter, offered by Thorlabs, with a catalog number ND240B. This filter is unmounted, making it a versatile option for various optical setups. The filter's primary function is to reduce the intensity of incident light without altering its color composition, making it an essential tool for managing light intensity in optical systems.

The filter is rectangular in shape, with a base shape of Thin Lens, and measures 50 mm in width and 50 mm in height. It has a thickness of 2 mm, providing a sturdy yet compact design. The filter is made of N-BK7 Schott, a high-quality optical glass known for its excellent transparency and low auto-fluorescence, ensuring high-quality optical performance.

The ND240B filter features a front and back coating of tho nd40, a reflective neutral density coating. This coating provides an Optical Density of 4.0, which corresponds to a transmission of approximately 0.01%. This high optical density makes the filter ideal for applications requiring extreme light attenuation, such as high-power laser systems.

The filter's coating and material are designed to work optimally at a wavelength of 633 nm. However, due to the nature of neutral density filters, the filter maintains a consistent attenuation across a wide spectrum of wavelengths, making it a versatile option for various optical applications.

The ND240B filter is currently in stock and available for purchase through the provided weblink. With its high-quality materials, precise dimensions, and high optical density, the ND240B filter is a reliable and efficient solution for managing light intensity in optical systems.