64-681 12.5 mm Dia. Traditional Coated OD 2.0 Longpass Filter; t=1.5mm 1075nm

The 64-681 is a Longpass Filter, a type of optical filter that passes longer wavelengths of light and blocks shorter wavelengths, from the renowned optical components vendor, Edmund Optics. This particular model boasts a 12.5 mm diameter and a thickness of 1.5mm, making it suitable for a wide range of optical applications.

The filter is designed with a cut-on wavelength of 1075nm, meaning it begins to transmit light at this wavelength and beyond. The cut-off wavelength, on the other hand, is 0nm, indicating that it blocks all wavelengths shorter than 1075nm. This specific characteristic makes it ideal for applications where the detection of longer wavelengths is crucial, such as infrared (IR) spectroscopy or astronomy.

The 64-681 model features a circular base shape, a common design for optical components due to its ease of alignment and integration into optical systems. The filter is made from UVFS Mal-1965 material, a type of optical glass known for its excellent transmission properties and durability.

The filter's coating is another notable feature. Both the front and back surfaces are coated with EDM 64-681, a proprietary coating developed by Edmund Optics. This coating enhances the filter's performance by reducing surface reflections and improving transmission, thereby increasing the overall efficiency of the optical system.

The filter's shape is described as Thin Lens, suggesting that it may have some lens-like properties, such as focusing or magnifying light. However, without more specific information, it's difficult to definitively state its lens capabilities.