Radial servo device for super-resolution optical disc and servo control method therefor

A servo device for a super-resolution optical disc, comprising an excitation light source, servo light source, integrated optical path, focusing unit, servo light detection unit, and drive control unit;

• the excitation light source emits excitation light, and the servo light source emits servo light, and the excitation light and the servo light reach the focusing unit through the integrated optical path, being focused on the disc surface, the servo light passes through the focusing unit again after being reflected on the disc surface, and then the reflected light is detected by the servo light detection unit, and the detection result is transmitted to the drive control unit;
• the excitation light source comprises at least one laser light source with a single wavelength or laser light source with different wavelengths;
• the integrated optical path at least comprises a collimator lens, which integrates the servo light and the excitation light to form a coaxial circular parallel beam;
• the focusing unit at least comprises an optical element capable of focusing and focuses the excitation light and the servo light on the same axis;
• the servo light detection unit detects the servo reflected light beam generated by the servo light beam converged by the focusing unit and reflected by a servo guide layer of the super-resolution optical disc;
• the drive control unit presets N detection error reference values for the detection signal of the reflected light generated by the servo guide layer of the servo light irradiating optical disc, and controls the radial position of the focusing unit according to a comparison result of the detection result of the servo reflected light and the detection error reference value, wherein N is an integer greater than 1.