Sunday, February 16, 2014 5:29:59 PM
The term "infrared" covers wavelengths from thousands of nanometers (think body heat) to about 700nm, which is just below visible red. The light used to transmit data in many devices via fiber optics or free-space optics, as Nickel2 pointed out, work up in the nearly visible range around 710nm to 1100nm. So yeah, IR easily passes through glass.
Sunday, February 16, 2014 5:12:28 PM
That's well done. Now here`s an even more fun question: Why does glass partially reflect some small amount of photons? (check out Feynman`s little book "QED: The Strange Theory of Light and Matter" for the answer. It`s a great down-to-earth explanation of the overall behavior of light).