Extending the method developed in a previous paper [1] the correlation functions both for electric field strength and intensity are calculated. In the latter case the result is obtained quite easily by solving a differential equation. In the first case, on the contrary, a detailed knowledge of the photon creation operator b+ is necessary, especially of the different temporal behaviour with respect to phase and amplitude. In the main, the results are in agreement with those published by other authors. Of special interest is the result that the damping constant for intensity correlations tends to the value corresponding to the case of thermal radiation, in the region far from threshold.

In addition, the ansatz b+ = (ro + ϱ) exp{i χ(t)} (roc-number) introduced by HAKEN is discussed from a quantum mechanical point of view.