Novel architectures of Petawatt-class, high peak power laser systems that allow operating at high repetition rates are opening a new arena of commercial applications of secondary sources and discovery science. The natural path to higher average power is the reduction of the total heat load induced and generated in the laser gain medium and eliminating other inefficiencies with the goal to turn more energy into laser photons while maintaining good beam quality. However, the laser architecture must be tailored to the specific application and laser parameters such as wavelength, peak power and intensity, pulse length, and shot rate must be optimized. We have developed a number of different concepts tailored to secondary source generation that minimize inefficiencies and maximize the average power. The Scalable Highaverage- power Advanced Radiographic Capability (SHARC) and the Big Aperture Thulium (BAT) laser are examples of two such high average power laser concepts; SHARC is designed for production of ion beams and x-rays, and exploration of high energy density physics at 1.5 kW average power, and BAT is envisioned for driving laser-based electron accelerators at 300 kW average power.