ABSTRACT
One application of beam shaping is to improve signal quality in optical data storage systems. 1 Since the light source in an optical data storage device is a coherent laser beam, simple beam-shaping techniques can greatly influence the performance of the system. Beam-shaping elements take the form of spatially dependent optical filters that are strategically placed in the light path. This chapter discusses theory, simulations, and practical implementation for beam-shaping techniques used in optical data storage. The storage and retrieval of data on optical disks are described in two simple steps. First, data marks are recorded on a surface. The second step is retrieval of the information from the disk, where a focused light beam scans the surface. Modulation in the reflected light is used to detect the data-mark pattern under the scanning spot.
