Optical sensor which produces a micro-spot beam on data recording carrier for recording optical information with high density in order to record larger quantities of data

摘要

The optical sensor includes collimator lens (4) for converting a divergent flow emitted by semiconductor laser (1), into collimated flow, and an objective lens (6) which receives on data recording carrier (7) flow output converged by the beam-forming device (5), which forms a ray having a given proportion between longer and shorter diameter elliptic cross-section. The beam forming device shortens the longer diameter elliptic cross-section and increases the shorter diameter elliptic cross-section. The light splitting device (3) splits the light flow reflected at data recording carrier in the direction of the semiconductor laser and a direction different from that of semiconductor laser, and the diffraction element (2) bends the reflected flow at data recording carrier and steers the bent flow to a photodetector (8).