US 6,982,821 B2 | ||
Optical beam position active sensing using satellite beams | ||
David L. Hecht, Palo Alto, Calif. (US) | ||
Assigned to Palo Alto Research Center Incorporated, Palo Alto, Calif. (US) | ||
Filed on May 22, 2003, as Appl. No. 10/443,725. | ||
Prior Publication US 2004/0233510 A1, Nov. 25, 2004 | ||
Int. Cl. G02F 1/33 (2006.01) |
U.S. Cl. 359—305 | 49 Claims |
1. A beam position sensing system comprising:
a beam source configured to generate a directed beam;
a satellite beam generator aligned to receive the directed beam and to transmit a main beam and generate a pair of symmetric
satellite beams having time-varying deflection angles from the main beam;
a first detector arrangement positioned to detect a first satellite beam of the pair of satellite beams and generate a first
detector signal; and
a second detector arrangement positioned to detect a second satellite beam of the pair of satellite beams and generate a second
detector signal,
wherein the first detector signal and the second detector signal are used to determine an absolute position of the main beam.
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