This invention relates to optical fiber arrays and more particularly to high precision optical fiber array connectors.
The use of optical fibers in communication systems is rapidly expanding due to the large bandwidth capabilities of optical fibers. With the development of optical cross connect switches, the use of optical fibers will increase. One challenge in construction of large-scale optical cross connect switches is that optical fibers must be precisely aligned to the switching element in order to allow for switching of an optional signal between optical fibers. Many current attempts to align and hold fibers work only for 1 dimensional arrays. One attempt to deal with this problem is discussed in U.S. Pat. No. 5,907,650 entitled “High Precision Optical Fiber Array Connector and Method” issued to Sherman et al. This patent discloses shaping the end of the optical fiber into a cone shape, inserting the cone shaped ends into openings in a mask to engage the surface wall and then bonding the fibers in place. This approach has drawbacks which include the requirement that the optical fibers must be processed such that one end of the optical fiber is essentially conical in shape.
Thus, a need has arisen for an improved optical fiber array connector that overcomes disadvantages associated with other connectors.
In one embodiment, a fiber optic array connector is disclosed. The fiber optic array includes a first faceplate having a plurality of openings with sidewalls. The first faceplate is oriented in a first direction. The fiber optic array also includes a second faceplate having a plurality of openings with sidewalls. The second faceplate is oriented in a second direction. Optical fibers are inserted through the plurality of openings in the first faceplate and the plurality of openings in the second faceplate. The second faceplate and the first faceplate are adjusted such that the sidewalls in the openings in the first faceplate and the sidewalls in the openings in the second faceplate contact and hold the optical fibers.
In another embodiment, an optical cross-connect switch is disclosed. Optical cross connect includes a fiber optic array having a plurality of optical fibers, the optical fibers held by an optical array connector. The optical array connector includes a first faceplate having a plurality of openings and a second faceplate having a plurality of openings. The plurality of openings in the first faceplate are aligned in a first direction. The plurality of openings in the second faceplate are aligned in a second direction. Optical fibers are inserted in to the plurality of openings in the first optical array and the openings in the second optical array. The second faceplate and the first faceplate are adjusted such that the optical fibers are secured against the openings of the first faceplate and the second faceplate.
Technical benefits of the present invention for an improved fiber array connector include a simplified way to hold an optical fiber. Also, using the fiber optic array of the present invention can be used to form a cross connect switch where the optical fibers are aligned with great accuracy. Other technical benefits are apparent from the following descriptions, illustrations and claims.
For a more complete understanding of the device and advantages thereof, reference is now made to the following descriptions in which like reference numerals represent like parts:
a is an exploded view of an array connector;
b is an exploded view of an array connector showing the adjustment of the faceplates;
c is an exploded view of an array connector showing the securing of the faceplates; and
d is an exploded view of an array connector having three faceplates showing the adjustment of the faceplates.
Also illustrated is a mirror array 104. Mirror array 104 comprises a two dimensional array of individual mirrors 107. Each mirror 107 of mirror array 104 can be moved to help direct light to the proper location. Mirror array 104 is preferably manufactured using Micro Electronic Manufacturing System (MEMS) technology. Mirror array 104 of this design is manufactured by Lucent Technologies. A reflector 106 is also provided. Reflector 106 is a plane mirror operable to direct light to and from the mirrors 107 of mirror array 104.
In operation, communication signals 110 in the form of modulated beams of light are transmitted along certain optical fibers 108 in optical fiber array 102. The communication signals 110 exit an optical fiber 108 in optical fiber array 102 and are directed by a mirror 107 in mirror array 104 to reflector 106 and from reflector 106 back to another mirror 107 in mirror array 104. The communication signal 110 is then reflected back to a different optical fiber 108 in fiber array 102. In this manner communicational signals 110 carried by optical fibers 108 can be switched from one optical fiber 108 to another optical fiber 108 without converting the optical signals to electrical signals. The optical fibers 108 must be held together closely with each optical fiber 108 aligned with a high degree of accuracy so the communication signals 110 can be switched from one optical fiber 108 to another. Thus the array connector 105 needs to be able to hold the optical fibers 108 securely together and at precise alignment.
Faceplate 200 is preferably made from a material such as silicon or silicon dioxide. The thickness of the faceplate is selected to maximize the strength of the faceplate while minimize cost of manufacturing. In one embodiment, faceplate 200 is approximately 0.4 millimeters thick. Openings 202 are formed in faceplate 200 using conventional techniques such as conventional photolithographic techniques to form the shape of the openings followed by deep reactive ion etching to form the openings. Deep reactive ion etching produces uniform trenches while preserving the openings 202 sidewall integrity. For ease of handling, faceplate 200 may be placed in a housing 204, manufactured from stainless steel or similar material.
Openings 202 in one embodiment are essentially teardrop in shape with a rounded side 206 and a v-shaped side 208. Other shapes can also be used. Opening 202 is large enough to accept an optical fiber 108. In order to accommodate a typical optical fiber 108 having a diameter of 125 μm, opening 202 can be at least 300 μm in diameter.
The faceplates 200 and 300 are designed to move in relation to each other in order to secure optical fibers 108 by clamping the optical fibers 108 against a side of the openings 202 and 302, such as against the v-shaped sides 208 and 304. In one embodiment, bottom faceplate 300 moves while top faceplate 202 is held in place. Or, the order of movement can be reversed. Alternatively both faceplates can be moved in opposite directions. Movement can be accomplished by a conventional robotic system attached to the faceplates 200 and 300.
After optical fiber 108 is held in position, conventional glue, such as an ultra-violet light curable epoxy can be applied to further hold optical fibers 108 in position. The fiber array connector 105 is then leveled by cutting any extending optical fiber 108 flush with top faceplate 200. After that, faceplate 200 and ends of optical fibers 108 can be polished using conventional means. Additionally optimal coatings may be applied.
In operation, for the two-faceplate embodiment shown in
b is an exploded view of an array connector showing the movement of a faceplate. Alignment pins 830 and 832 can be inserted through alignment hole 710 and elongated adjustment hole 806 and alignment hole 712 and elongated adjustment hole 808 respectively. This locks top faceplate 700 in place while bottom faceplate 800 can be moved a short distance because of the elongated shape of adjustment holes 806 and 808. The bottom faceplate 800 is moved to secure optical fibers (not shown in this picture) against the sides of openings 202 and 824.
c shows top faceplate 700 and bottom faceplate 800 using clamping holes 702, 704 and 802, 804. Clamping pin 820 and 822 are inserted through top faceplate 700 and bottom faceplate 800, after the optical fibers 108 are inserted through the openings 724 and 824 and the faceplates 700 and 800 are aligned to secure optical fiber 108.
d illustrates an embodiment with three faceplates. Illustrated are a top faceplate 700, a middle faceplate 900 and a bottom faceplate 950. Middle faceplate 900 is aligned in the opposite direction of top faceplate 700 and bottom faceplate 950. In this embodiment, when pins 970 and 972 are inserted, middle plate 900 can move in order to secure optical fibers 108.
Having now described preferred embodiments of the invention modifications and variations may occur to those skilled in the art. The invention is thus not limited to the preferred embodiments, but is instead set forth in the following clauses and legal equivalents thereof.
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3597659 | Hoffman et al. | Aug 1971 | A |
3985975 | Steensma | Oct 1976 | A |
5590229 | Goldman et al. | Dec 1996 | A |
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6482593 | Walt et al. | Nov 2002 | B1 |
Number | Date | Country | |
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20030223700 A1 | Dec 2003 | US |