Active Directory Autnetication to use username in application?

Is there a way to use Windows Active Directory Autheitcation to get the username of the user thats accessing a CodeIgniter web application?

I have a small database that tracks user changes, etc. and would like to make it have as few logins as possible. Thanks for your help

I haven't had a chance to implement Active Directory authentication myself, but the following library looked promising when I looked into it:
https://github.com/adldap/adLDAP

Bonfire

Practical CodeIgniter 3
CodeIgniter Testing Guide

Thanks mwhitney! That looks helpful. I'll try to implement that and post how it goes here