FBH520-40 Premium Bandpass Filter; Dia:25 mm; CWL=520nm; FWHM=40nm

The FBH520-40 Premium Bandpass Filter is a high-quality optical component designed for precise wavelength selection, manufactured by Thorlabs. This filter features a circular shape with a diameter of 25 mm and a thickness of 2 mm, making it compatible with a wide range of optical systems.

The filter is specifically designed for a central wavelength (CWL) of 520 nm, with a full width at half maximum (FWHM) of 40 nm. This means it allows light within a 40 nm range around the central wavelength to pass through while blocking other wavelengths. This characteristic makes it ideal for applications that require narrowband wavelength filtration, such as fluorescence microscopy, spectroscopy, and laser systems.

The FBH520-40 filter is made from UVFS material, identified as MAL-1965 in Thorlabs' catalog. It comes with anti-reflection coatings on both the front and back surfaces, denoted as 'tho fbh520-40'. These coatings are designed to minimize reflection and increase transmission, enhancing the filter's performance in your optical setup.

The filter's physical data includes a cut-on wavelength of 500 nm and a cut-off wavelength of 540 nm. This means it starts transmitting at 500 nm and stops at 540 nm, effectively filtering out wavelengths outside this range.

In terms of shape, the filter is designed in a Thin Lens configuration, which can be beneficial in certain optical arrangements. It is currently in stock and available for immediate purchase through Thorlabs' website, as indicated by its valid weblink status.