摘要 |
<p>An optical pick-up device uses a holographic optical element that includes a holographic optical element, formed by combining a birefringence medium and an isotropy medium, for adjusting an optical route of a transmitted beam according to a polarizing direction and wavelength of an incident beam. The optical pick-up device has an objective lens for focusing the beam pass through the holographic optical element on an optical disk according to the wavelength of such beam.</p> |