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Aberration correction apparatus and method

  • US 6,690,500 B2
  • Filed: 06/21/2001
  • Issued: 02/10/2004
  • Est. Priority Date: 06/30/2000
  • Status: Expired due to Fees
First Claim
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1. An aberration correction unit disposed in an optical path of an optical system for irradiating a recording medium with a light beam for correcting aberration produced in said light beam, said aberration correction unit comprising:

  • a first electrode and a second electrode being opposed to each other; and

    a liquid crystal, disposed between said first electrode and said second electrode, for producing a holographic diffraction grating effect by applying a voltage across the liquid crystal to produce a change in phase to light passing therethrough, wherein at least one of said first electrode and said second electrode is formed in a partitioned shape such that said liquid crystal produces a holographic diffraction grating effect because of the partitioned shape when applying voltages to said first electrode and said second electrode.

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