A storage medium is provided that includes a magnetic recording tape having a first side and a second side, and a plurality of optically detectable indicia embedded in a servo layer disposed between the first side and the second side of the tape. The optical reflectivity and/or phase of the indicia are...http://www.google.com.au/patents/US20050057836?utm_source=gb-gplus-sharePatent US20050057836 - Magnetic media with embedded optical servo tracks
