[en] A high intensity dye laser pumped by a copper vapor laser, with a 4KHz repetition rate and energy of 5 mj/pulse was constructed and characterized. Two configurations were investigated. The first was a dye laser constructed as a Hansch-type power oscillator with a 2 GHz bandwidth. It was found that the overall efficiency of the laser did not exceed 17 percent for either of the two laser dyes rhodamine B (pumped by both 511 and 578 nm copper vapor laser wavelengths) or rhodamine 6B (pumped only by the 511 nm line). The second was a master oscillator-power amplifier. The Hansch-type oscillator was pumped by a small fraction of the copper vapor laser output. The transversely-pumped amplifier received most of the pumping energy. The beam from the oscillator passed through spatial and spectral filters before entering the amplifier dye cell, whose entrance face was at Brewster angle to the beam. In order to achieve maximum energy and efficiency, the dependence of the amplifier efficiency on all the relevant amplifier parameters was investigated. Under optimum conditions a total system efficiency of 0.46 for rhodamine 6G (amplifier efficiency of 0.50) and 0.30 for rhodamine B (amplifier efficiency of 0.33). For the experimental conditions investigated an approximated analytical solution for the accepted theoretical system of dye amplifier rate equations was found. Comparison of the calculated efficiencies with the experimental results for various sets of amplifier parameters was very good