1. The problem statement, all variables and given/known data My textbook on lasers has mentioned thermal conductivity a few times, but hasn't specifically mentioned it's importance. I'm at a part talking about Nd:Glass lasers and it says that glass has a lower thermal conductivity than Nd:YAG lasers, which prohibits continuous wave (CW) operation and limits the pulse repetition frequency in pulsed operation to a few Hz. My first idea was that low thermal conductivity would be bad for semiconductor and solid-state lasers because if the heat isn't spread out over the gain medium then it could cause stress/damage of that one part of the gain medium, and that it would be much harder to cool a certain area of the gain medium, whereas with higher thermal conductivity you could have a uniform cooling across the whole gain medium without having to worry about hotspots. Am I missing something? I'm imagining thermal conductivity isn't really mentioned in regards to gas or dye lasers because it's so low, compared to that of solid-state and semiconductor lasers.