The transverse profiles and evolution of the laser intensities of a high-power copper HyBrID laser (510.6 nm, 578.2 nm) are presented. Both the radial profiles and temporal evolutions of the laser pulse intensities are markedly different in a large- bore (6 cm) HyBrID laser than in conventional elemental metal copper vapor lasers of similar dimensions. The differences in laser intensity distributions and their temporal evolution are attributed to the electron-attaching properties of hydrogen and bromine in the laser buffer gas mixture of a HyBrID laser. The significantly low conductivity of the gas in a HyBrID laser means that the plasma skin effect is relatively weak and does not influence the development of laser oscillation to any great extent; oscillation in a 6 cm bore HyBrID laser begins on the tube axis first and at the wall 3-4 ns later; the time-averaged laser intensity peaks on the tube axis.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.