FF02-809/81-25 25 mm Dia. 809/81nm BrightLine Single-Band Bandpass Filter by Semrock

Semrock's FF02-809/81-25 is a Bandpass Filter, specifically designed for use in optical systems that require precise wavelength selection. This filter is circular in shape, with a diameter of 25 mm and a thickness of 2 mm, making it compatible with a wide range of optical components.

The filter is made from UVFS MAL-1965 material, a high-quality optical material known for its excellent transmission properties and durability. The FF02-809/81-25 is designed to pass wavelengths around 809 nm, with a full width at half maximum (FWHM) of approximately 81 nm. This makes it ideal for applications that require narrowband wavelength selection in the near-infrared region.

The filter's physical data includes a cut-on wavelength of 768.5 nm and a cut-off wavelength of 849.5 nm. This means that it effectively blocks wavelengths outside of its passband, reducing unwanted noise and improving signal-to-noise ratios in optical systems. The center wavelength (CWL) of the filter is 809 nm, providing a precise and reliable wavelength reference.

The FF02-809/81-25 features Semrock's proprietary FF coating on both the front and back surfaces. This coating is designed to enhance the filter's performance, providing high transmission, low autofluorescence, and excellent environmental stability. The coating also helps to reduce surface reflections, improving the overall efficiency of the optical system.

In terms of shape, the filter is designed as a Thin Lens, which can help to minimize optical aberrations and improve the focus of the optical system. The filter is currently in stock and available for purchase through the Semrock website.