Comparison of Potential Ceramic Gain Media

The real advantage of the laser driver as compared to other drivers is its ability to provide a high quality focal spot on target. Heat generation in solid-state media has always been recognized as a limiting feature because at high repetition rate, the quality of this focal spot depends on the beam wave-front distortions. It is not easy to design the driver baseline because there are too many different parameters to deal with. In this paper, we introduce two figures of merit that show that Yb doped ceramics (either garnets or sesquioxides) are promising laser materials opening new fields during the research phase to demonstrate ignition and fusion gain (including the fast ignitor concept). When driven at low temperature (cryogenic cooling), all of the operational features of the laser amplifier can be demonstrated at an aperture scale of only 10-15 cm.