Lucas is steadily inching up in popularity with parents who want something similar to but more substantial than Luke, to the point where it ranks Number 16, its highest place ever.
Lucas has long been a favorite of TV scriptwriters, from the early black-and-white days of The Rifleman (Chuck Connors as Lucas McCain) to the schoolteacher series Lucas Tanner to the more contemporary One Tree Hill, and the name appears as Lucas Beauchamp in William Faulkner's Intruder in the Dust and Light in August.
Lucas Cranach was an important German Renaissance painter and printmaker; Lucas Samaras is an eccentric Greek-born American contemporary artist. Some will associate the name with director George Lucas.
At the moment Lucas is enjoying a tremendous international success. It is currently the Number 1 name in Sweden and Number 4 in the Netherlands.
Note that Lucas and Luke derive from a different root and have a different meaning than Lucius and Lucian.