| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup equipped with a wave surface (phase) correction phase modulation element a thin and light phase difference plate where the function of a transmissive wave surface difficult to be disturbed even during thermal expansion, especially a bandwidth phase difference plate, is integrated. <P>SOLUTION: This optical pickup includes a laser light source, an objective lens, and a phase modulation element having a birefringnt material held between two transparent substrates arranged between the laser light source and the objective lens. In this case, the phase modulation element has a structural birefringent structure formed in the transparent substrate surface on a side opposite the birefringent material. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
