An apparatus for combining coherent light from a plurality of coherent light sources is provided. The apparatus includes a plurality of light guides, each including: a first mirror at an entrance face, including an aperture for admitting light therein from a respective one of the plurality of coherent light sources; and a second partially-reflective mirror at an exit face. The apparatus further includes a second stage light guide, for combining emitted light exiting the plurality of light guides, including: a second stage entrance face and a second stage exit face, the second stage entrance face for receiving the emitted light from each the exit face of the plurality of light guides; and a third mirror, at the second stage exit face, for reflecting the light back towards the second mirror, the third mirror including an exit aperture for the light to exit the second stage light guide.