This page includes discussion about various current topics in radiometry as well as some links that I have found to other sources of information. It is still under construction. One topic of current interest to me involve the proper usage of our symbols, units and nomenclature. High on the list is the proper and improper usage of the term intensity . Another personal area of interest is blackbody radiation simulation.
Blackbody radiation is inherently lambertian.
Some of the newer designs, taking their cue from effective light-trapping structures, sacrifice lambertian characteristics to achieve a higher effective emissivity in a preferred direction. This is typically accomplished using a specular black surface in the cavity rather than a diffuse black. Indeed, the use of a specular black in a light trap can significantly increase the absorptance for some directions at the expense of others. Trap detectors are of great interest in the radiometry community. The earliest trap detector that I have seen dates back near the turn of the century, the Smithsonian water-flow pyrheliometer.