Patent ID: 6958957

Claim:
A method of calibrating a crosstalk correction for a tracking error signal (TES) to a focus error signal (FES) crosstalk, comprising: choosing a cross-talk gain from a set of cross-talk gains, the cross-talk gain determining a fraction of a tracking error signal from a tracking servo system to subtract from a focus error signal in a focus servo system to form an adjusted focus error signal in the crosstalk correction; performing a Bode calculation to obtain a frequency component of the adjusted focus error signal at a frequency in response to a perturbation of the tracking servo system at the frequency; comparing the component with components resulting from previous values of the cross-talk gain, each of the previous values of the cross-talk gain being of the set of cross-talk gains; and replacing an optimized cross-talk gain with the cross-talk gain if the component is lower than previous components.