Triplet Collimator Lens Design of Blu-ray Disc Optical Pick-up

During the design process of Blu-ray Disc Optical Pick-Up (BD OPU), the optical system design plays a significant role, and the collimator lens design is especially important. According to the PW optical design formulas, this paper calculates the initial parameters of collimator lens. It chooses the triplet type collimator lens instead of aspheric lens to design in order to reduce the manufacture difficulty according to the real situation in China. And then based on the initial parameters of collimator lens, the paper optimizes the triplet collimator lens to reach a good quality effect of parallel beam. At last it puts these design data into manufacture and adjusts the distance between the LD and the collimator lens by using the sleeve mechanism structure to see the real effect of collimating. Finally the assembly experiment of whole BD OPU validates these design that it can be used in BD OPU very well.