The 68-661 is a 50 mm diameter Infrared (IR) Longpass Filter, manufactured by Edmund Optics. This filter is designed with a traditional coating, featuring a catalog number of 68-661. The filter is currently in stock and available for purchase through the official Edmund Optics website, linked below.
https://www.edmundoptics.com/p/450mum-50mm-diameter-infrared-longpass-filter/23279/
The 68-661 filter is a Longpass Filter, a type of optical filter that passes longer wavelengths of light and blocks shorter wavelengths. This particular filter has a cut-on wavelength of 4500nm, meaning it begins to transmit light at this wavelength and beyond. The cut-off wavelength is 0nm, indicating that it blocks all wavelengths of light below 4500nm.
The filter is made from Germanium Burnett, a material known for its excellent optical properties, particularly in the infrared region of the spectrum. The filter has a diameter of 50mm and a thickness of 1mm, making it suitable for a wide range of optical applications.
The 68-661 filter is coated on both the front and back surfaces with EDm 33-971, a proprietary coating developed by Edmund Optics. This coating enhances the filter's performance and durability, ensuring reliable operation in demanding environments.
The filter's shape is described as a Thin Lens, indicating that it has been designed to minimize optical aberrations and distortions. This makes it an ideal choice for applications that require high-precision optical performance.