FGL9 Dia:25 mm RG9 Colored Glass Filter; 721nm Longpass

The FGL9 Dia:25 mm RG9 Colored Glass Filter is a high-quality optical component sourced from Thorlabs, a leading vendor in the field of optical equipment. This filter is specifically designed for use in applications that require longpass filtering at 721nm.

The filter is made from n-bk7 Schott, a type of glass known for its excellent optical properties. It has a circular base shape with a diameter of 25mm and a thickness of 2mm, making it suitable for a wide range of optical systems. The filter is coated on both the front and back with the THo FGL9 coating, which enhances its performance and durability.

The FGL9 filter is a color glass filter, a type of filter that uses colored glass to block specific wavelengths of light while allowing others to pass through. In this case, the filter is designed to cut on at 721nm, meaning it begins to block light at this wavelength, and has a cut off of 0, indicating it blocks all wavelengths below this point.

The filter is shaped as a thin lens, which is a type of lens with a very small thickness compared to its diameter. This shape allows the filter to be easily integrated into various optical systems without causing significant distortion or aberration.

According to the vendor's website, the FGL9 filter is currently in stock, indicating it is readily available for purchase and use. Further information about this filter, including detailed specifications and purchasing options, can be found at the provided weblink.