Bose condensates from the point of view of laser physics

The dynamic analogy between the Bose condensate of photons (laser), Bose condensate of atoms, and Bose condensate of Cooper pairs in a superconductor is discussed. It is pointed out that the coherent state of Bose condensates of different types can appear only due to stimulated transitions.The equations are discussed that combine into a unified dynamic system the order parameter of the Bose condensate and the concentration of atoms beyond the condensate for an ensemble of atoms captured by a trap, as well as the order parameter of Cooper pairs, the concentration of free quasi-particles, and the densities of phonons and photons in a semiconductor.