Nature Photon. 6, 195–200 (2012); published online 12 February 2012; corrected after print 11 July 2012.

In the version of this Article originally published, the measured temperature difference ΔT was at the detector plane, whereas the definition of noise-equivalent temperature difference (NETD) in equation (2) requires ΔT to be a thermal scene temperature difference. Thus, the NETD terminology in equation (2) has now been replaced with temperature sensitivity (TS). This error has been corrected in the HTML and PDF versions of the Article.