Patent ID: 8451702

Claim:
An optical storage system that receives an optical medium having a plurality of tracks for storing data, the system comprising: an optical head having optics that split a light beam into a higher power main beam and at least one lower power side beam that form corresponding spots spaced along a selected one of the plurality of tracks; at least one controller coupled to the optical head that selectively positions the optical head for writing data along the selected one of the plurality of tracks using the higher power main beam while reading data directly after writing from the selected one of the plurality of tracks using the at least one lower power side beam; and a correlation detector that determines a correlation between a write signal provided to the higher power main beam that is time shifted based on transit delay of the optical medium moving between the main beam and the at least one side beam, and a read signal from the at least one lower power side beam after the transit delay, wherein valid data is determined based on the correlation exceeding a corresponding threshold.