Mirror drift compensation in an optical circuit switch
View Patent ↗Methods of operating an optical circuit switch and optical circuit switches are disclosed. To make a connection between a first port and a second port, baseline voltages may be determined, baseline voltages being voltages that, if respectively applied to one or more electrode coupled to a first mirror element uniquely associated with the first port and one or more electrode coupled to a second mirror element uniquely associated with the second port, cause the first and second mirror elements to rotate to make the connection in the absence of accumulated mirror element drift. Accumulated drift data associated with one or both of the first mirror element and the second mirror element may be retrieved from a memory. One or more of the baseline voltages may be modified based on the accumulated drift data to provide corrected voltages, and the corrected voltages may be applied to the electrodes.
1. A method for making a connection from a first port to a second port through an optical circuit switch, comprising:
determining baseline voltages that, if respectively applied to one or more electrode coupled to a first mirror element uniquely associated with the first port and one or more electrode coupled to a second mirror element uniquely associated with the second port, cause the first and second minor elements to rotate to make the connection in the absence of accumulated minor element drift;
retrieving, from a memory, accumulated drift data associated with one or both of the first minor element and the second mirror element;
modifying one or more of the baseline voltages based on the accumulated drift data to provide corrected voltages;
applying the corrected voltages to the electrodes;
receiving a break command to break the connection between the first port and the second port;
applying at-rest voltages to the electrodes; and
periodically decaying the accumulated drift data associated with one or both of the first and second mirror elements in accordance with a predetermined decay function.
2. The method of claim 1 , further comprising:
periodically adjusting the voltages applied to the electrodes to minimize an insertion loss of the connection; and
periodically updating the accumulated drift data associated with one or both of the first and second mirror elements based on differences between the adjusted voltages applied to the electrodes and the respective baseline voltages.
3. The method of claim 1 , wherein the decay function is linear.
4. The method of claim 1 , wherein the decay function is exponential.
5. The method of claim 1 , wherein the decay function is stored in a lookup table.
6. The method of claim 1 , wherein the accumulated drift data comprises differences between the adjusted voltages applied to the electrodes and the respective baseline voltages.
7. An optical circuit switch, comprising:
a first port;
a second port;
a controller configured to:
determine baseline voltages that, if respectively applied to one or more electrode coupled to a first mirror element uniquely associated with the first port and one or more electrode coupled to a second mirror element uniquely associated with the second port, cause the first and second minor elements to rotate to make a connection from the first port to the second port in the absence of accumulated minor element drift;
modify one or more of the baseline voltages based on stored accumulated drift data associated with one or both of the first and second minor elements to provide corrected voltages;
cause the corrected voltages to be applied to the electrodes to make the connection from the first port to the second port;
receive a break command to break the connection between the first port and the second port;
cause respective at-rest voltages to be applied to the electrodes; and
periodically decay the accumulated drift data associated with one or both of the first and second mirror elements in accordance with a predetermined decay function.
8. The optical circuit switch of claim 7 , wherein the controller is further configured to:
periodically adjust the voltages applied to the electrodes to minimize an insertion loss of the connection; and
periodically update the stored accumulated drift data associated with one or both of the first and second mirror elements based on differences between the adjusted voltages applied to the electrodes and the respective baseline voltages.
9. The optical circuit switch of claim 7 , wherein the decay function is linear.
10. The optical circuit switch of claim 7 , wherein the decay function is exponential.
11. The optical circuit switch of claim 7 , wherein the decay function is stored in a lookup table.
12. The optical circuit switch of claim 7 , wherein the accumulated drift data comprises differences between the adjusted voltages applied to the electrodes and the respective baseline voltages.