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| Method of compactly storing digital data |
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Shape memory alloy optical fiber switch
| Details |
Inventors: Jebens, Robert W.;
Assignee: AT&T Bell Laboratories (Murray Hill, NJ)
Primary Examiner: Sikes; William L.
Assistant Examiner: Ngo; John
Attorney, Agent or Firm: Herndon; Jerry W., Nelson; Gordon E.
An optical fiber switch in which a switchable fiber is switched to a first position by a first member inside the housing made of a shape memory material. This first member attempts to restore itself to an original shape heated above a first temperature and, in so doing, exerts a switching force on the switchable fiber. In a preferred embodiment, biasing means push the switchable fiber into a second position when the first means is below a second temperature. The first member exerts a force on the switchable fiber in a direction opposite to that of the biasing means of sufficient force to overcome the biasing force when the first member is above the first temperature. When the shape memory member is cooled, it assumes a distorted shape which allows the biasing means to control the position of the switchable fiber. In one embodiment, the biasing means is a second member also made of a shape memory material. In this embodiment, the first and second shape memory members are heated and cooled in opposite phases to achieve switch operation and release. |
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DETAILED DESCRIPTION In FIG.
1, a switch is shown as a double pole switch.
That is, two sets of fibers are switched and released at the same time.
However, this is not a limitation of the invention.
In principle, any number of sets of fibers may be switched.
Two fixed optical fibers 104 and 106 enter a switch housing 102 from one side of the switch assembly.
On the opposite side, a switchable fiber 108 enters housing 102 and is optically aligned (switched) with one or the other of the fixed fibers 104 and 106.
As mentioned above, a second set of fibers 110, 112 and 114 also enter the switch housing 102.
However, since the details of operation are identical for the second set of fibers, the discussion will proceed only with respect to the first set.
In the following discussion, reference is made only to a single switch element, it being understood that, in principle, any number of switch elements may be contained in a single assembly.
The switch housing 102 comprises two base members 116 and 118.
These base members may be made of metal, plastic or other suitable material.
A number of colinear vee groove sections 120, 122, 124 and 126 support and align switchable fiber 108 and fixed fiber 106.
Base member 116 contains matching vee groove sections 128, 130, 132 and 134.
Grooves 120 and 128 are of sufficient depth to fixedly contact and hold the switchable fiber 108 when the base members are brought together.
Actually, the depth of the groove sections 120 and 128 are chosen such that the base members 120 and 128 do not touch each other, but are slightly separated when brought together.
This is to insure that the fiber 108 is positively clamped.
The remaining groove sections 122, 124, 126 and the corresponding mates in base member 116 are greater in depth sufficiently to clamp the two fixed fibers 104 and 106.
In addition, both base members 116 and 118 may have mating aligning vee grooves 136 and 138, respectively, for receiving an alignment fiber 140.
Other means of aligning the base members together may be provided, if desired
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I/O Systems 
