US 6,983,005 B2 | ||
Holographic laser and optical pickup | ||
Katsushige Masui, Nara (Japan); and Kazuhiro Tsuchida, Nara (Japan) | ||
Assigned to Sharp Kabushiki Kaisha, Osaka (Japan) | ||
Filed on Jan. 24, 2002, as Appl. No. 10/56,255. | ||
Claims priority of application No. P2001-016289 (JP), filed on Jan. 24, 2001; and application No. P2001-394848 (JP), filed on Dec. 26, 2001. | ||
Prior Publication US 2002/0097773 A1, Jul. 25, 2002 | ||
Int. Cl. H01S 3/00 (2006.01); H01S 3/30 (2006.01); G11B 7/135 (2006.01) |
U.S. Cl. 372—109 | 21 Claims |
1. A holographic laser comprising:
a first light source for emitting a light beam L1 of a first wavelength toward an optical disk;
a second light source for emitting a light beam L2 of a second wavelength different from the first wavelength toward an optical disk, the second light source being positioned
near the first light source;
a wavelength separating element for separating the light beam L1 and the light beam L2 reflected by the respective optical disks;
a first holographic element for converging the light beam L1 separated by the wavelength separating element;
a second holographic element for converging the light beam L2 separated by the wavelength separating element; and
a light receiving element for receiving the light beam L1 converged by the first holographic element and the light beam L2 converged by the second holographic element,
wherein the first holographic element is arranged at a position so that the light beam L1 of the first wavelength emitted from the first light source toward the optical disk does not pass through the first holographic
element and the light beam L1 of the first wavelength reflected by the optical disk passes through the first holographic element;
wherein the second holographic element is arranged at a position so that the light beam L2 of the second wavelength emitted from the second light source toward the optical disk and the light beam L2 reflected by the optical disk pass through the second holographic element;
wherein the light receiving element is positioned between a focal position of 0th order diffracted light of the first holographic
element and a focal position of 0th order diffracted light of the second holographic element; and
wherein the first light source, the second light source, the wavelength separating element, the first holographic element,
and the second holographic element are integrally formed into a single component.
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