The 85-908 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 1200 nm wavelength. This filter is sourced from Edmund Optics and is available for purchase directly from their website.
The Bandpass Filter features a Hard Coated OD 4.0 with a 50 nm bandwidth, centered at 1200 nm. The cut-on wavelength is specified at 1175 nm, while the cut-off wavelength is at 1225 nm. This filter is designed to transmit light within the specified bandwidth while blocking light outside of this range, making it ideal for applications that require high spectral contrast and rejection of out-of-band signals.
The filter is made from UVFS Mal-1965 material and features a Thin Lens shape. The front and back surfaces of the filter are coated with EDM 85-884, providing excellent durability and resistance to environmental factors. This coating also enhances the filter's performance by reducing surface reflections and improving transmission efficiency.