Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium
Reexamination Certificate
1998-04-16
2001-06-12
Edun, Muhammad (Department: 2651)
Dynamic information storage or retrieval
Specific detail of information handling portion of system
Radiation beam modification of or by storage medium
C369S044140
Reexamination Certificate
active
06246657
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the optical switching of light, and more particularly to the optical switching of light in an optical data storage and retrieval system.
BACKGROUND ART
A number of optical switch technologies are currently used for controlling the optical passage of light. With one technology, electric current is applied to a polymer to create a thermal effect that changes a refractive index of a polymer. As the refractive index changes, a light beam passing through the polymer is selectively routed from an input to an output. Although faster than a comparable mechanical optical switch, the switching time of polymer optical switches is limited significantly by the thermal characteristics of the polymer. Additionally, the optical properties of the light transmitted through the polymer are undesirably affected by the optical characteristics of the polymer.
Another optical switch is disclosed by Leslie A. Field et al., in “The 8
th
International Conference on Solid-State Sensors and Actuators, and Eurosensors IX, Stockholm, Sweden, Jun. 25-29, 1995.” The optical switch is micro-machined in silicon and uses a thermally activated actuator to mechanically move a single send optical fiber relative to two receive optical fibers. Field et al. exhibits relatively slow mechanical movement due to inherent thermal effects. Additionally, Field et al. provides only one degree of optical alignment, resulting in inefficient transfer between optical fibers due to slight misalignments.
Another micro-machined optical switch is disclosed by Levinson in U.S. Pat. No. 4,626,066. Levinson uses a cantilevered micro-machined mirror that is electrostatically positioned between a stopped and unstopped position. While Levinson's mirror may deflect light between two optical fibers, as with the aforementioned switch designs, it also is capable of optical alignment in only one dimension.
What is needed is an optical switch that provides fast and precise switching of light between an input and a plurality of outputs, or vice versa.
SUMMARY OF THE INVENTION
The present invention permits fast and precise optical switching of light between an input port and a large number of output ports in a volumetric space that is very compact.
The present invention directs a first beam of light along an optical path between an input and an output. The present invention includes an optical assembly comprising a front surface, a back surface, and an optical axis disposed between the front surface and the back surface;
The present invention further includes an actuator assembly. The actuator assembly selectively directs the first beam of light between the front surface and the actuator assembly with a selected angular orientation relative to the optical axis. The optical assembly directs the first beam of light between the front surface and the back surface. The back surface comprises a plurality of output locations, and individual ones of the plurality of output locations correspond to individual ones of the plurality of angular orientations.
The present invention further comprises a plurality of optical fibers. The plurality of optical fibers each comprise a proximal end and a distal end. The proximal ends of the optical fibers are aligned in the optical path to direct the first beam of light between a particular one of the plurality of output locations and a particular one of the distal ends. In one embodiment, the proximal ends are disposed within a housing. In another embodiment, the proximal ends are disposed in a closely packed pattern. In one embodiment, the optical assembly comprises a GRIN lens.
In the present invention, the actuator assembly comprises a first actuator and a second actuator. The first actuator comprises a first arm and a first reflector coupled to the first arm. The first reflector reflects the first beam of light at a first reflection point and the first arm rotates about a first rotation axis. The second actuator comprises a second arm and a second reflector coupled to the second arm. The second reflector reflects the first beam of light at a second reflection point and the second arm rotates about a second rotation axis. In one embodiment, the first and second actuators comprise voice coil motors. The first rotation axis falls along a horizontal plane passing a vertical distance above the point of reflection of the beam of light from the second reflector. The vertical distance is defined by approximately a distance from the reflection point of the first beam of light from the second reflector to the front surface of the optical assembly. The second rotation axis falls along a vertical plane approximately coextensive with the front surface of the optical assembly. The second reflection point is disposed along the optical path between the first reflection point and the front surface of the optical assembly. A portion of the first beam of light is directed towards a beam splitting element to exit the beam splitting element as a second beam of light. The present invention further comprises a detector. An optical position of the second beam of light is detected the detector, and the actuator assembly directs the first beam of light based on the optical position of the second beam of light. The first reflector reflects the second beam of light at a third reflection point and the second reflector reflects the second beam of light at a fourth reflection point. The optical position of the second beam is detected by the detector after the second beam is reflected from the third and fourth reflection points.
The present invention may be used in an optical disk drive to selectively direct the first beam of light towards a particular storage location.
REFERENCES:
patent: 4239330 (1980-12-01), Ashkin et al.
patent: 4265513 (1981-05-01), Matsushita et al.
patent: 4304460 (1981-12-01), Tanaka et al.
patent: 4498730 (1985-02-01), Tanaka et al.
patent: 4626066 (1986-12-01), Levinson
patent: 4838631 (1989-06-01), Chande et al.
patent: 4896937 (1990-01-01), Kraetsch et al.
patent: 4978190 (1990-12-01), Veith
patent: 5000532 (1991-03-01), Kraetsch et al.
patent: 5024500 (1991-06-01), Stanley et al.
patent: 5208880 (1993-05-01), Riza et al.
patent: 5260928 (1993-11-01), Lee et al.
patent: 5446811 (1995-08-01), Field et al.
patent: 5452283 (1995-09-01), Lee et al.
patent: 5493440 (1996-02-01), Souda et al.
patent: 5532884 (1996-07-01), Lee et al.
patent: 5647033 (1997-07-01), Laughlin
patent: 295 17 012 U1 U (1996-02-01), None
patent: 2 178 869 (1987-02-01), None
patent: 6310402 (1994-04-01), None
patent: WO 92/07356 (1992-04-01), None
“Micromachined 1×2 Optical Fiber Switch”, L. Field, D. Burriesci, P. Robrish, R. Ruby,Transducers'95, Jun.25-29, 1995, pp. 344-347.
Article by M. Edward Motamedi, Ming C. Wu and Kristofer S.J. Pister entitled “Micro-opto-electro-mechanical devices and on-chip optical processing,” May 1997, pp. 1282-1297.
Heanue John F.
Hrinya Stephen J.
Huang Yonglin
Hurst, Jr. Jerry E.
Wilde Jeffrey P.
Edun Muhammad
Flehr Hohbach Test Albritton & Herbert LLP
Iolon, Inc.
LandOfFree
Fiber bundle switch does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fiber bundle switch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber bundle switch will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2531730