The content type CMS_LINKTARGET prints raw target attribute, which is set through CMS_LINKEDITOR content type.
The usage is very simple. Just put CMS_LINKTARGET in target attribute in your module like below.
Note
If you are using more then one CMS_LINKTARGET per article, you have to change/increment index of the next CMS_LINKTARGET .
$target = "CMS_LINKTARGET[1]"; echo '<img src="path/to/source" alt="alt" target="'.$target.'" />';