Title:
OPTICAL PICKUP, OPTICAL RECORDING/REPRODUCING DEVICE, COMPUTER, OPTICAL DISK RECORDER, AND MINUTE SPOT FORMING METHOD
Document Type and Number:
WIPO Patent Application WO/2011/048811
Kind Code:
A1
Abstract:
Provided are an optical pickup, an optical recording/reproducing device, a computer, an optical disk recorder, and a minute spot forming method, which enable the propagation of light at high transmittance and formation of a minute spot.
An optical pickup is provided with a wavelength plate (202) which converts the polarization state of an optical beam emitted from a semiconductor laser (101), and an objective lens optical system (105) which focuses the optical beam, the polarization state of which is converted, with a numerical aperture exceeding 1, the wavelength plate (202) generates the optical beam having a polarization state that differs according to location, the polarization distribution of the optical beam generated by the wavelength plate (202) is axisymmetrical with the optical axis of the optical beam as a symmetrical axis, a ray on the optical axis is circularly polarized light, some of rays other than the ray on the optical axis are elliptically polarized light with an ellipticity less than 1, and in each elliptically polarized light, the angle formed by the long axis of the ellipse and the circumferential direction of a circle around the optical axis is less than plus or minus 45 degrees.
Inventors:
SANO KOUSEI
Application Number:
PCT/JP2010/006226
Publication Date:
April 28, 2011
Filing Date:
October 20, 2010
Export Citation:
Assignee:
PANASONIC CORP (JP)
SANO KOUSEI
SANO KOUSEI
International Classes:
G11B7/135
Foreign References:
| JP2000171612A | 2000-06-23 | |||
| JPH09145921A | 1997-06-06 |
Attorney, Agent or Firm:
KOTANI, Etsuji et al. (JP)
Etsuji Kotani (JP)
Etsuji Kotani (JP)
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