EFFICIENCY CONTROLLED DIFFRACTION GRATING AND OPTICAL PICKUP HAVING THE DIFFRACTION GRATING

摘要

PROBLEM TO BE SOLVED: To produce a complex grating pattern such as a grating lens by forming a first transparent electrode, a grating layer and an insulating layer on a transparent substrate, forming a post layer on a portion of the insulating layer and forming a second electrode which functions as a reflection mirror. ;SOLUTION: The efficiency controlled diffraction grating is made by piling up a first transparent electrode 22, a grating layer 23 which has repeated grating patterns with reflection and transparent sections, an insulation layer 24, a post layer 25 located at an edge section and a second electrode 26, which also works as a reflection mirror, on a transparent substrate 21. By controlling the voltage applied between the electrodes 22 and 26, the gap between the electrode 26 and the layer 23 is varied and the efficiency of a first order diffraction is controlled. Thus, the layer 23 is fixed the electrode function is eliminated from the construction, the diffraction grating having various grating patterns is formed and the durability is made superior.;COPYRIGHT: (C)1998,JPO