Some applications require the isolation of a specific spectral band. Filtering the undesired spectral band prior to diffraction helps to minimize second order and ray scattering effects as well as maximizing the spectral dynamic range. This is generally achieved by placing an optical filter ahead of the diffraction grating within a system; however mounting a separate optical filter may not be possible, particularly due to space limitations.
For such situations, Laser Components offers filtered diffraction gratings. A filter coating is applied directly to the surface of the diffraction grating, eliminating the need for a separate filter element. Filtered diffraction gratings are available in both reflective and transmissive configurations.