We demonstrate a frequency doubled dual-gain quantum dot semiconductor disk laser operating at 590 nm. The reflective gain element, grown by molecular beam epitaxy, has active region composed of 39 layers of InGaAs Stranski- Krastanov quantum dots. The gain mirrors produce individually 3 W and 4 W of output power while the laser with both elements in a single cavity reveals 6 W at 1180 nm with beam quality factor of M2<1.2. The loss induced by the nonlinear crystal is compensated by gain boosting in the dual-gain laser and 2.5 W of output power at 590 nm was achieved after frequency conversion.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.