85-904 50 mm Dia. Hard Coated OD 4.0 50nm Bandpass Filter; t=3.5 mm 1000nm

The 85-904 is a Bandpass Filter with a 50 mm diameter and a thickness of 3.5 mm, designed for use in optical systems requiring a narrow passband around the 1000 nm wavelength. This filter, offered by Edmund Optics, features a hard coating on both the front and back surfaces, ensuring durability and resistance to scratches and environmental factors.

The filter's physical data includes a cut-on wavelength of 975 nm and a cut-off wavelength of 1025 nm, with a central wavelength (CWL) of 1000 nm. This specificity in wavelength control allows for efficient filtering of unwanted spectral components, enhancing the performance of optical systems in various applications.

The 85-904 filter is made of UVFS Mal-1965 material, which is known for its excellent optical properties and performance in the near-infrared region. The filter's geometry, with a 50 mm diameter and 3.5 mm thickness, ensures a compact and robust design suitable for integration into various optical setups.

The coating on this filter is EDM 85-880, a multi-layer dielectric coating that provides high transmission and excellent environmental stability. This coating enhances the filter's performance by minimizing reflection and absorption losses, thereby increasing the overall efficiency of the optical system.