I have done this one month ago. I know you can do it with different domains...I don't know how in laravel, but tomorrow I will post a link here, very good, I can't find it right now. I used to do an Single Sign On AUthentication system. I did it using multiple apps under the same domain and server (IF YOU USE MORE SERVERS, I THINK you have to use memcache or redis or something in common and acces there 'driver' => 'redis',... ), using different subdmains for each one. You need to modify the config files, and say that you use that domains..And in my case I put same app key. (I think must be same, I didn't really try with different, but I thought that and I did it from the beginning)

for each one:

'cookie' => 'laravel_session_APP_NAME',  


'domain' => '*.yourdomain.com', 

'secure' => false,  //if you only use HTTPS