OPTICAL PICK-UP SYSTEM USING SOLID IMMERSION LENS WITH HIGH NUMERICAL APERTURE AND LARGE TOLERANCE

摘要

An optical pick-up system of high numerical apertures having large tolerance is provided to maintain stable performance without recognition rate drop by forming solid immersion lens to increase numerical apertures and reduce the size of a light spot. An optical pick-up system of high numerical apertures having large tolerance comprises: an objective lens focusing light coming from a light source and forming a light spot on a optical disc; and a solid immersion lens being installed between the objective lens and the optical disc and increasing numerical apertures and reducing the size of the light spot. The light permeation distance which is from the vertex of the solid immersion lens to the focus of the light is greater than light permeation distance at the hemispheric solid immersion lens and is smaller than the light permeation distance at the hyper solid immersion lens.