Latent heat of a homogeneously broadened two-mode laser

A homogeneously broadened two-mode laser exhibits metabistability and a first-order phase transition, with a discontinuous order parameter. The entropy is therefore discontinuous, and one can define a quantity that is analogous to the latent heat for a thermodynamic system. This is calculated for the laser, and shown to depend only weakly on the asymmetry of the laser.