Hi. I have 2 questions about second-order coherence – g2(t): 1) For collision-broadened light according to the literature g2(t)=1+|g1(t)|^2, where g1(t) is the 1st order coherence. Therefore for very low collision rate g1(t) =1 and thus g2(t)=2. However I would expect collision broadened light to reach a costant phase limit of CW for low collision rate and thus g2(t)=1. What did I miss here? 2) In a light emitting diode – LED there should be many different scattering mechanisms for the radiating carriers and thus it should behave as a collision-broadened light g2(0)=2 with super-poissonian photon statistics. On the other hand the literature about LEDs talks about poissonian and even sub-poissonian photon statistics dependent only on the electron current and ignoring the scattering. Does anyone have a simple explanation of what should LED’s g2(t) look like and why?