Googled infrared burners on grills and got this article:
Chars a steak on the outside but leaves it rare in the middle.
What if I told you there's a grill that will cook foods in half the time of any other grill? A grill that can produce the kind of heat necessary to char a 1" steak on the outside but leave it rare in the middle. A grill that can reach cooking temperatures above 700oF. How, you ask? The Infrared Burner. The infrared burner works by focusing the flame of a standard gas burner onto a ceramic tile that has thousands of microscopic holes in it. This converts the heat of the flame into infrared energy, the same energy you feel from the sun on a cold day. This heat is much higher and more persistent than a standard grill can produce.
Sounds like it concentrates heat to cook quicker (or burn faster if you don't watch it).