find out the previous URL and the value after hash # in Laravel

i'm developing a Laravel app. i'm looking for a way to figure out which page the user is coming from to save that value in the session and redirect to it later. so far i've found that you can use methods such as URL::previous() and Redirect::back()->getTargetUrl() to get the previous URL. however, the problem is that these methods do not grab the value after the URL hash. so, if a user is coming from a URL like this:

http://ift.tt/2bg9oMG

the ouput of the aforementioned methods is:

http://example.com

how can i grab the full URL, including the value after hash?

via Chebli Mohamed