Light dims and brightens when in sleep mode

when i put my macbook in sleep mode (closing the lid) the light on the front right next to the black IR dot constantly dims right down and then brightens back up really bright and then dims down again only to brighten right back up. It takes only about 3 seconds for this all to happen. I was just wondering if this is normal or if something is faulty and perhaps the power is being surged, hence the reason for it to go dim and then to go bright again. This happen to anyone else?

That's exactly what it's supposed to be do when it indicates that it's sleeping.

okay, thanks alot Professor Jay, i just didn't want to be naive to a potential problem.