The Way of Kings|
Katarotam is a lighteyed Alethi of whom Kaladin does not think highly.
That's how lighteyes were. Roshone, Amaram, Katarotam ... 
It is likely that he was one of Kaladin's early masters shortly after becoming a slave.
Complete:This page has sparse information from the books. However, it does contain everything we have on the subject at this time.