Hi A!
Lukas (
Luke is an English version) is a Latin name meaning "from the landscape Lucania in Italy". But the place name "Lucania" derives from the Greek word for "bright, white, light" as well:
http://www.lucaniaonline.it/Storia%20della%20Lucania.htm
There are hundrets of names with the same root which are seen as completely different names nowadays. In this "light" category you could put some more names like
Lucia, Luzie, Laux, Luckel, Luch etc.
By the way - there are Frisian male names Luk (pronounced like English
Luke) and
Luke (pronounced with a hearable e at the end) which derive from the name Ludeke which is a pet form of names like
Ludwig, Luitfried, Luitbrand, Luitbald etc. The first part of the name (Luit/Lud/Lu) meaning "people". Same look - totally different meaning! ;-)
Regards,
Satu