Laser-detector-grating-unit

摘要

A bar-shaped grating beam-splitter 10 is used for the generation of focus error, tracking error, forward sense and high frequency signal. The beam-splitter is made in bars ( 40 ) and is secured to wafer consisting of a plurality of detector chips ( 14 ). Securing the bar in position is preferable to securing separate grating beam-splitters individually. Individual light detector grating units are then separated from the wafer.