Infrared reflective optical interference film

The present invention provides an optical interference film, made of multiple layers of polymers, which reflects wavelengths of light in the infrared region of the spectrum while being substantially transparent to wavelengths of light in the visible spectrum. The optical interference film includes multiple alternating layers of at least first, second, and third diverse, substantially transparent polymeric materials A, B, and C, with the layers being of an optical thickness of between about 0.09 and 0.45 micrometers. Each of the polymeric materials has a different index of refraction, ni, and the refractive index of the second polymeric material is intermediate the respective refractive indices of the first and third polymeric materials.