The regex expression [^"] is a character class, the caret meaning, as you say, negation - 'anything but what follows'. The * after that means matc zero or more of them, greedily. The parentheses capture what's matched in $1. The enclosing quotes are matched literally. The result is that everything between the first and second quote is captured.

Another way would be to use a non-greedy expression in the capture, /"(.*?)"/

After Compline,
Zaxo