Typically in the old days one would use a flash tube to pump a ruby crystal. Is there any way, or any lasing material, that could use concentrated sunlight directly for either continuous or pulsed operation? I am familiar with some attempts but the materials available seem rather limited
They already exist. "Solar-pumped lasers already exist: they work by concentrating sunlight onto crystalline materials such as neodymium-doped yttrium aluminium garnet, causing them to emit laser light." (source) They have been innovated though, so there are more efficient method to make solar-powered lasers now.