The 66236 Dichroic Beam Turning Mirror is designed for high reflectance and polarization insensitivity over a limited 280 to 400 nm primary spectral range. Most of the IR is transmitted through the dichroic mirror and absorbed by the 3 Inch Series model 66247 mirror housing (not included) where a heat sink dissipates the heat. It does not remove all of it. We have found that enough infrared is removed to make some irradiation studies practical without further filtering. If further filtering is required, use a liquid filter to remove infrared intensity.