ETH Zurich researchers demonstrated a thermal trap that reached 1,050 degrees Celsius under concentrated artificial illumination. The laboratory device combined a quartz rod with a ceramic absorber: light passed through the quartz to heat the absorber, while the arrangement reduced radiative heat losses. The experiment used a rod 7.5 centimetres wide and 30 centimetres long, illuminated at an intensity equivalent to 135 suns.
The work targets process heat for industries such as cement and steel, where high temperatures are usually supplied by combustion. Published in Device, it extended thermal trapping well beyond the temperatures previously demonstrated with that approach. This was a laboratory heat-generation experiment, not an operating industrial furnace; technical and economic assessment of a scaled system remained outstanding.
