Add query param to url in the Laravel Controller

Is it possible to add a param to the url from the route Controller?

For example my url is: http://ift.tt/2utvAwv

And his method controller is:

getOrderFinished() {
  // I want add this param
  http://ift.tt/2vEVADN
}

I want the final url http://ift.tt/2vEVADN, but I must add the param order_number from the controller method.

via Chebli Mohamed