Hot and cold mirrors “heat control filters” are types of dichroic filters used to remove unwanted energy from a light emitting source.
Hot Mirror
A hot mirror is a dichroic filter that reflects 90% of near infrared (NIR) and infrared (IR) light while transmitting up to 80% of the visible light. Hot mirrors transmit the shorter wavelengths and reflect the infrared energy. Hot mirrors can be specified for an angle of incidence ranging from aero to 45 degrees. They are made by applying a multi-layer dielectric coating to the glass substrate such as Borofloat® borosilicate glass.
Cold Mirror
A cold mirror is a dichroic filter that reflects up to 90% of the visible light spectrum while allowing transmission of infrared wavelengths IR and near IR of up to 80%. Cold mirrors reflect the shorter wavelengths and transmit the heat (infrared). A cold mirror can be specified for an angle of incidence ranging from zero to 45 degrees. They are made by applying a multi-layer dielectric coating to the glass substrate such as Borofloat® borosilicate glass.
Abrisa Technologies provides these heat control filters in thicknesses of 1.1mm, 1.7rmm and 3.3mm in sizes of up to 24” in diameter.