Hot Mirror IR Filters
A hot mirror is a piece of glass with an added heat reflective filter.
The filter (generally a dichroic filter) reflects/blocks infrared light allowing visible light to pass through. This reduces heat to build up from a light source, reducing damage to components.
Actual achieved heat reduction is dependent upon the light source used as well as the application.
Application: Hot mirrors are used for their capability to reduce heat and are often used in fibre optic systems to protect the glass fibres from overheating or burn out.
Hot mirrors are also used for photography whereby certain cameras are sensitive to infrared. Other uses include iridescent bulbs, projectors and heat sensitive systems.