jQuery - add element after text

i have a navigation with some links:

<ul class="nav">
 <li>
  <a class="active">linkname</a>
 <li>
</ul>

now i need to add extra content directly after "linkname" like this:

<ul class="nav">
 <li>
  <a class="active">linkname<b class="caret"></b></a>
 <li>
</ul>

how can i add elements (div,span,b) directly after specific text?