The JavaScript method window.openwill open a new window. You can combine this technique with a link to achieve your goal. Here is an example of this method, taken from official documents. Just substitute your destination URL for http://example.com.
<a href="https://plus.google.com/share?url=http://example.com"
onclick="javascript:window.open('http://example.com','',
'menubar=no,toolbar=no,resizable=yes,scrollbars=yes,height=600,width=600');
return false;">
<img src="https://www.gstatic.com/images/icons/gplus-64.png"
alt="Share on Google+"/>
</a>
source
share