The Hanbury and Twiss Effect. A journey to my understanding?

The Hanbury Brown and Twiss effect can be viewed as the birth of quantum optics and is the cornerstone of intensity interferometry astronomy. In the case of optical intensity interferometry where detectors observe a stream of individual photons the effect is quantum mechanical. Some semi-classical explanations for the HBT effect, taught in University courses, are misleading and leave many students frustratd, with little understanding of the effect. I will show that the HBT effect can be understood semi-classically by including the effects of stimulated emission.