Heat Control Filters are mainly used to remove the heat from high-power illumination systems. These high power illumination systems offer a very high output in the visible and ultraviolet which makes them an excellent choice as a source of radiation. However, there is one major drawback to these systems; they produce a high amount of heat. This radiation (heat) must be removed from the optical system and the most effective way to do so is to use a combination of Heat Control Filters.

The optical system should be configured so that the first mirror in the system is a Cold Mirror mounted at 45° to the incident radiation. This configuration will transmit a major portion of the systems heat while reflecting the visible light. The second component in the optical path should be a hot mirror mounted perpendicular to the light beam. This mirror will reflect the remaining heat while still transmitting 90% of the visible light.