| 摘要 |
PURPOSE:To facilitate the manufacture of the polarization beam splitter and the optical head device using the splitter and to improve the precision. CONSTITUTION:This splitter has a substrate 1 made of a birefringent material having an uneven periodic grating formed on the top surface and a birefringent layer 2 which is formed on at least a projection part 1a between the projection part 1a and a recessed part 1b of the birefringent refracting substrate 1 and is different from the material of the birefringent substrate 1; and the thickness d2 of the birefringent material layer 2 and the recessed part depth d1 of the substrate 1 are so set that one of the phase difference of ordinary light and the phase difference of extraordinary light between the recessed part and projection part is an even multiple of pi. |
