  We report the optical excitation-dependent output photocurrent
characteristics of GaN-based polariton diode lasers operated under reverse-bias
at room temperature. The photocurrent demonstrates a non-linear enhancement at
an incident optical power of ~ 1.6 mW, which is approximately equivalent to the
value of polariton lasing threshold observed when the diodes are operated under
forward bias conditions. This is explained in the framework of an Auger-like
process of excitonic dissociation into its constituent electron-hole pairs,
which can be stimulated by the occupation of the polariton lasing states. The
observed effect is a remarkable manifestation of the bosonic final state
stimulation in polariton lasers. A model based on the coupled kinetic equations
for the free carriers, the excitonic reservoir and the polariton condensate
shows a good agreement to the experimental data.
