Changing the output frequency of a giant high energy chemical laser is extremely tricky. Frequency doubling demands a very pure coherence to get good efficiency, and even then "good" in this context means above 50% power converted to the new frequency. With a weapons laser, you're going to have a hell of a cooling problem in the converting medium. Then again, if reflective anti-laser coatings become common, it shouldn't be too difficult to add on a free electron laser system to burn off the mirror layer before the main beam strikes. A free electron laser can change operating frequencies trivially, just by adjusting its internal magnetic field.
It's a chemical laser but in solid, not gaseous, form. Put simply, in deference to you, Kent, it's like lasing a stick of dynamite. As soon as we apply a field, we couple to a state, it is radiatively coupled to the ground state. I figure we can extract at least ten to the twenty-first photons per cubic centimeter which will give one kilojoule per cubic centimeter at 600 nanometers, or, one megajoule per liter.
Beware of Programmers who carry screwdrivers. -- Leonard Brandwein