High average power solid state lasers in the 2 - 3 kW-range with fiber transmission are now available and higher power systems are under development in the labs. A review is given on the latest efforts to increase output power and improve beam quality. Highlights are the lamp pumped systems: 3 kW-Nd-YAG, cw and pulsed, 1.7 kW-Q-switched Nd:YAG, 0.2 kW-Ti- Sapphire, 0.1 kW-fundamental-mode laser, using phase conjugation. Besides these conventional systems new pumping schemes are operating in the lab. Diode pumped lasers up to 1 kW were realized and lamp pumped systems up to 10 kW are within reach in the next years. A very exciting new development is the direct application of high power diode lasers in material processing. Diode output powers of about 50 W can be transmitted by 500 micrometers - fibers, 100 W will be available in the near future. Although many efforts were made to grow better crystals, the results are disappointing with concern to high power. Only one promising new system was proposed recently and is under investigation in the lab, the Ytterbium-YAG crystal.
"New developments in the field of solid state lasers", Proc. SPIE 2502, Gas Flow and Chemical Lasers: Tenth International Symposium, (31 March 1995); doi: 10.1117/12.204881; https://doi.org/10.1117/12.204881