| 摘要 |
PURPOSE: To provide an integrated type optical pickup device capable of performing focus control without carrying out motor driving. CONSTITUTION: The optical pickup is constructed in a manner that a grating coupler 15 for converging light beams introduced from a laser diode 20 to a wave guide 12 into a disk 21 by diffracting these upward on a substrate, a grating beam splitter 18 for dividing reflective light beams from the disk 21 and photodiodes 19a to 19d for detecting the reflective light beams divided by the grating beam splitter 18 are formed on the substrate having the wave guide 12 formed thereon in an integrated manner. The wave guide 12 is formed on a p-type substrate 11 with an MQW structure and an n-type layer 13 is formed thereon. Electrodes 16 and 17 are provided in the upper and lower parts of the wave guide 12 in order to perform focus control by applying voltages and controlling the effective refractive index of the wave guide 12. |
