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激光头读取光盘上信息轨迹的过程是:激光二极管发射出的激光束经过光栅分束镜将一束光分为三束光。中间一束为主光束(在前),用于拾取声、象信息和聚焦误差信息;两侧为辅助光束(在后),用于拾取循迹误差信息。三束光平行通过半反射透镜,阻止垂直极化光束通过.又经(1/4)λ(激光波长)镜片产生90°的相位延迟,变为圆形极化光束,经平行透镜和物镜精确地照射在光盘上的信息轨迹上(信息轨
Laser head to read the information on the disc track is: the laser diode laser beam emitted through the grating splitter will be a beam of light into three beams of light. The middle one is the main beam (front), which is used to pick up the sound, image information and focus error information; the two sides are the auxiliary beam (after) for picking up the tracking error information. The three beams pass through the semi-reflective lens in parallel to prevent the passage of the vertically polarized beam and a phase delay of 90 ° from the (1/4) λ (laser wavelength) lens becomes a circularly polarized beam that is precisely collimated by the lens and objective To irradiate the information track on the disc (information track