MEMS Mirror Switching Speed and Residual Modulation Control
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Solution Overview
Problem
MEMS photonic switches face limitations in switching speed and residual modulation when used in cascade configurations, which affects their performance in photonic switched networks due to complex control methods and potential interference.
Innovation Solution
A micro-electro-mechanical-system (MEMS) mirror structure with a mirror support pillar and deflection electrodes, where the mirror is prevented from moving closer to or farther from the electrode plate by applying specific drive voltages, allowing for controlled rotational and linear motion to enhance switching speed and reduce residual modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex control methods are used to achieve precise mirror deflection, then the switching precision is improved, but the switching speed deteriorates
Solution Approach 1:
The control voltage is segmented into two independent components: a common-mode voltage applied to both deflection electrodes for rapid mirror deflection, and a differential-mode voltage applied between electrodes for precise positioning. This segmentation allows the system to achieve both fast switching and precise control by operating the two voltage modes independently and simultaneously.
Solution Approach 2:
The control method uses periodic switching between different voltage states to achieve rapid mirror deflection while maintaining precision. The common-mode voltage provides periodic actuation for fast response, while the differential-mode voltage continuously adjusts the precise position, creating a combined control rhythm that optimizes both speed and accuracy.
2Adaptability or versatility
If the mirror is allowed to move freely during switching, then the switching flexibility is improved, but residual modulation increases
Solution Approach 1:
The patent applies a preliminary constraint by positioning the mirror support pillar at a specific height above the electrode plate before switching occurs. This pre-established mechanical constraint prevents the mirror from undergoing unwanted linear motion during switching operations, thereby eliminating residual modulation while preserving switching flexibility through controlled rotational degrees of freedom.
Solution Approach 2:
The mirror support pillar acts as an intermediary mechanical element between the mirror and the electrode plate. It provides a stable reference position and prevents direct contact between the mirror and electrode, thereby eliminating residual modulation caused by uncontrolled linear motion while allowing controlled rotational switching movements.
3Object-generated harmful factors
If the mirror is constrained from linear motion, then residual modulation is reduced, but the control complexity increases
Solution Approach 1:
The mirror support pillar provides self-service by automatically maintaining the mirror at a fixed height above the electrode plate through its mechanical structure. This passive mechanical constraint eliminates the need for active control mechanisms to prevent linear motion, thereby reducing residual modulation without increasing control complexity. The system uses its own structural elements to enforce the constraint.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables faster switching speeds and reduced residual modulation, improving the performance of MEMS photonic switches in cascade configurations by preventing unwanted linear motion and maintaining a stable electric field, thus enhancing their scalability and reliability.
Implementation Method 1
a first deflection electrode and a second deflection electrode, where the second deflection electrode is opposite the first deflection electrode, where the first deflection electrode is configured to receive a first drive voltage, and where the second deflection electrode is configured to receive a second drive voltage
Implementation Method 2
a mirror support pillar disposed on the electrode plate, where the mirror support pillar has a bearing surface
Data Source
AI summary
In one embodiment, micro-electro-mechanical-system (MEMS) mirror structure includes an electrode plate including a first deflection electrode and a second deflection electrode, where the second deflection electrode is opposite the first deflection electrode, where the first deflection electrode is configured to receive a first drive voltage, and where the second deflection electrode is configured to receive a second drive voltage. The MEMS mirror structure also includes a mirror support pillar disposed on the electrode plate, where the mirror support pillar has a bearing surface and a mirror disposed above the bearing surface of the support pillar, where the mirror has a deflection angle, and where the first voltage is nonzero when the deflection angle is zero.