Abstract
We experimentally demonstrate the difference between a ridge polariton laser and a conventional edge-emitting ridge laser operating under electron-hole population inversion. The horizontal laser cavities are 20-60µm long GaN etched ridge structures with vertical Bragg refectors. We investigatethe laser threshold under optical pumping and assess quantitatively the effect of a varying optically-pumped length. The laser effect is achieved for an exciton reservoir length of just 15% of the cavity length, which would not be possible in a conventional ridge laser, with an inversionlesspolaritonic gain about 10 times larger than in equivalent GaN lasers. This combination of a very short injection section and a strong gain paves the way to compact microlasers with nonlinear functionalities for integrated photonics.