FSR-RG665 25.4 mm Dia. Colored Glass Absorptive Longpass Filter 665nm

The FSR-RG665 is a longpass filter with a 25.4 mm diameter, designed for use in optical systems that require the absorption of shorter wavelengths. This filter, offered by MKS/Newport, has a catalog number of FSR-RG665 and is available for purchase directly from their website. The filter's current status is "Valid - in stock," indicating it is readily available for immediate use.

The FSR-RG665 is a circular filter, made from a material identified as "uvfs mal- 1965." It has a thickness of 3 mm, which contributes to its durability and stability within optical systems. The filter's primary function is to allow light with wavelengths greater than or equal to 665 nm to pass through while blocking light with shorter wavelengths. This is achieved through a coating process, resulting in a front and back coating of "new rg665."

The filter's physical data includes a cut-on wavelength of 665 nm and a cut-off wavelength of 0 nm. This means that it begins to transmit light at 665 nm and continues to do so for all longer wavelengths. The filter's geometry is that of a thin lens, which can be beneficial in certain optical configurations.