Based on recent advances in diode laser technology we present experimental results for peak power, brightness, spectrum, and beam homogeneity of several low duty cycle pump modules with peak powers ranging from 2 kW to 80 kW. We will discuss their suitability for pumping Yb3+-doped laser materials. We will also propose beam delivery systems to scale the peak power of pump engines to the 100 to 1.000 kW range.