Control system for an optical fiber switch
First Claim
1. A method of controlling an optical switching fabric, comprising:
- periodically measuring current optimum positions of at least two reference mirrors on at least one mirror array; and
adjusting optimum positions for remaining mirrors on the at least one mirror array based on differences between the current optimum positions and previous optimum positions of the at least two reference mirrors.
2 Assignments
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Accused Products
Abstract
An optical switching fabric enables an optical signal entering the device on any one of multiple input ports to be directed to any one of multiple output ports. Light entering the switching fabric on an input port is reflected by individual mirrors on one or more mirror arrays to an output port. Methods of controlling optical switching fabrics compensate for distortions due to mechanical and environmental changes without the need to measure losses along all optical paths linking input ports and output ports. Reference input ports are interspersed among signal input ports and reference output ports are interspersed among signal output ports. Periodically, the positions of mirrors which maximize the intensity of light deflected from reference input ports and reference output ports, are measured. The measured positions are used to predict mirror positions to maximize the intensity of light deflected from signal input ports to signal output ports.
42 Citations
20 Claims
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1. A method of controlling an optical switching fabric, comprising:
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periodically measuring current optimum positions of at least two reference mirrors on at least one mirror array; and
adjusting optimum positions for remaining mirrors on the at least one mirror array based on differences between the current optimum positions and previous optimum positions of the at least two reference mirrors. - View Dependent Claims (2, 3)
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4. A method of controlling an optical switch, the method comprising:
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periodically measuring positions of mirrors in a first mirror array corresponding to reference input ports, the reference input ports being interspersed among signal input ports in an input fiber block, and positions of mirrors in a second mirror array corresponding to reference output ports, the reference output ports being interspersed among signal output ports in an output fiber block, the positions maximizing the intensity of reference light coupled from a reference light source to the reference input ports and directed to a reference light detector coupled to the reference output ports, via the mirrors in the first mirror array corresponding to the reference input ports and the mirrors in the second mirror array corresponding to the reference output ports, wherein the reference input ports and the reference output ports are dedicated to carrying reference light from the reference light source; and
using the measured positions of mirrors corresponding to the reference input ports and the reference output ports to predict positions for mirrors in the first mirror array corresponding to signal input ports and for mirrors in the second mirror array corresponding to signal output ports to maximize the intensity of signal light directed from signal input ports to signal output ports, via the mirrors in the first mirror array corresponding to the signal input ports and the mirrors in the second mirror array corresponding to the signal output ports. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method, comprising:
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performing a calibration of an optical fiber switch, wherein the optical fiber switch includes a first mirror array corresponding to input ports and a second mirror array corresponding to output ports; and
determining a number of reference input ports and a placement of reference input ports from among the input ports, and determining a number of reference output ports and a placement of reference output ports from among the output ports, wherein determining the number and placement of reference input ports and reference output ports comprises;
forming a connection grid wherein each point of the grid corresponds to a connection between a particular input port and a particular output port;
associating a vector of mirror positions with each point of the grid;
selecting candidate reference input ports and candidate reference output ports;
fitting functional forms to the vectors of mirror positions across rows and columns of the connection grid using points of the grid corresponding to connections between the candidate reference input ports and the candidate reference output ports; and
selecting reference input ports and reference output ports to minimize a difference, at all points of the grid, between mirror positions predicted by interpolation using the functional forms and the candidate reference input ports and candidate reference output ports and mirror positions optimized in the calibration. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification