Optical disk driver

Abstract

Light beams emitted from a light source (11) and returned light beams reflected off magneto-optical disks (7a), (7b), (7c), (7d) are transmitted by using polarization preserving optical fibers (15a), (15b), (15c), (15d). Phase difference generating means (16a), (16b), (16c), (16d) are disposed in the optical paths of the light beams, and the phase differences of electric field vibration components occurring in the light beams due to double refraction of polarization preserving optical fibers (15a), (15b), (15c). (15d) are offset by phase differences produced by phase difference producing means (16a), (16b), (16b), (16c), (16d), or the phase differences are adjusted to be multiples of pi .

Description

technical field [0001] The present invention relates to an optical disc drive which writes signals to and / or reads signals from an optical disc by irradiating light onto the disc, and more particularly, the present invention relates to an optical disc drive suitable for use by polarization maintaining ) An optical fiber drive that transmits the light used to write to and / or read signals from an optical disc. Background technique [0002] Heretofore, optical discs such as ROM (Read Only Memory) type optical discs typified by CD (Compact Disc) and RAM (Random Access Memory) type optical discs typified by phase change discs and magneto-optical discs have been widely used as recording media, To store information including images, sounds, characters, etc. [0003] For such optical discs, attempts have been actively made to increase recording density to increase storage capacity. Following this trend, various efforts have been made to improve optical disc...

AI Technical Summary

Problems solved by technology

[0009] However, even in the case where light is guided through such a polarization maintaining fiber, when a magneto-optical disk is used as the recording medium used with a conventional optical disk drive, the light returning from the magneto-optical disk will be incident on the polarization-maintaining fiber at a Kerr rotation angle , and thus create a phase difference between the field vibration components of the returning light guided through the polarization-maintaining fiber, and will adversely affect signal detection

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