Optical Filter With Slit Ring Electrodes for Gap Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable wavelength interference filters face challenges in accurately controlling the gap between reflecting films due to voltage noise, leading to inaccuracies in transmission wavelength control.
Innovation Solution
The optical filter configuration includes multiple electrodes on each substrate, with electrically isolated and connected pairs to enhance gap control accuracy, utilizing ring-like electrode shapes and slit designs to minimize parasitic capacitance and unwanted electrostatic forces, allowing for precise gap adjustment and reduced voltage sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a pair of electrodes is used to control the gap between reflecting films, then the device complexity is reduced, but the gap control accuracy deteriorates due to voltage noise sensitivity
Solution Approach 1:
The single electrode structure is segmented into multiple electrodes (first electrode, second electrode, third electrode, and fourth electrode) arranged in pairs. Each electrode pair independently controls the gap at different positions, distributing the control function and reducing sensitivity to voltage noise at any single location.
Solution Approach 2:
Multiple electrode pairs are combined to work together in controlling the overall gap between reflecting films. The first and second electrodes on the first substrate are paired with the third and fourth electrodes on the second substrate, creating a distributed control system that achieves both accuracy and reduced complexity.
2Measurement precision
If multiple electrodes are provided to control gap amount, then the gap control accuracy is improved, but the device complexity increases
Solution Approach 1:
The electrode system is segmented into distinct first and second electrodes on the first substrate, and third and fourth electrodes on the second substrate. This segmentation allows independent control of gap at different positions while maintaining a manageable structure through functional division.
Solution Approach 2:
Each electrode pair serves multiple functions: controlling gap at its specific position, providing electrostatic attraction for substrate alignment, and contributing to overall gap uniformity. This multi-functionality justifies the increased number of electrodes without proportionally increasing complexity.
3Object-generated harmful factors
If ring-shaped electrodes with slits are used, then parasitic capacitance is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The ring-shaped electrodes are segmented by introducing slits that divide each electrode into multiple sections. This segmentation breaks up continuous conductive paths, reducing parasitic capacitance between adjacent electrode regions while maintaining the overall ring structure for functional integrity.
Solution Approach 2:
The slits in the ring-shaped electrodes create asymmetric structures that deliberately disrupt symmetric capacitance distributions. By introducing intentional asymmetry through slit placement and orientation, the design controls and reduces parasitic capacitance effects that would otherwise arise from perfect symmetry.
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
This configuration enables high-accuracy gap control with reduced sensitivity to voltage noise, allowing for fine-tuned electrostatic attractive forces and improved transmission wavelength variability, eliminating the need for feedback control and enhancing the filter's stability.
Implementation Method 1
Such a variable wavelength interference filter generates electrostatic attractive force in accordance with a voltage applied to the electrostatic drive electrodes to control the gap
Data Source
AI summary
An optical filter includes: a first substrate; a second substrate opposed to the first substrate; a first reflecting film provided to the first substrate; a second reflecting film provided to the second substrate and opposed to the first reflecting film; a first electrode provided to the first substrate in a peripheral area of the first reflecting film; a second electrode provided to the first substrate in a peripheral area of the first electrode; a third electrode provided to the second substrate and opposed to the first electrode; and a fourth electrode provided to the second substrate and opposed to the second electrode.