System and method for precise servoing

A system for servoing when reading out a recorded holographic disk or recording in a preformatted holographic disk, the system comprising:

• a first detector configured to detect a primary signal of a reflected primary beam from a target data track of a target data layer of the holographic disk, the primary beam comprising a first wavelength, wherein the first detector is further configured to detect a power distribution of the reflected primary beam;
• a second detector configured to detect a tracking signal of a reflected tracking beam from a reference layer of the holographic disk the tracking beam comprising a second wavelength, wherein the second detector is further configured to detect a power distribution of the reflected tracking beam;
• a processing sub-system comprising:
• a comparator configured to compare a power measurement of the primary signal with a threshold value of power;
• at least one servo error generator configured to generate either a primary servo error signal based on the primary signal or a tracking servo error signal based on the tracking signal;
• and
• a servo controller configured to either generate an actuation signal based on the primary servo error signal in an event that the power measurement is greater than or equal to the threshold value, or generate an actuation signal based on the tracking servo error signal in an event that the power measurement is lesser than the threshold value;
• and
• an optical sub-system configured to actuate based upon the actuation signal such that the primary beam focuses on the target data layer.