Fabry-Perot Filter Voltage Control for Measurement Stability
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Solution Overview
Problem
Existing optical measurement systems using Fabry-Perot interference filters face issues with voltage overshoot, leading to potential sticking and instability during wavelength control, which can result in inaccurate measurements.
Innovation Solution
The optical measurement system gradually increases the potential difference between mirror portions to control the wavelength, preventing overshoot and ensuring stable measurements by allowing the voltage to rise gradually until it reaches the set value, and includes a standby time to stabilize temperature and reduce wavelength variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If voltage is rapidly applied to control the wavelength, then the response speed is improved, but overshoot occurs causing the gap to become smaller than target and sticking may occur
Solution Approach 1:
The patent applies preliminary action by gradually increasing the voltage from 0V to the target voltage in staged increments (e.g., 0V → 5V → 10V → target voltage) before the measurement is actually needed. This gradual voltage application prevents overshoot and pull-in phenomenon, ensuring the movable substrate reaches the target gap position accurately without causing sticking, thus resolving the contradiction between fast response and measurement stability.
2Loss of time
If voltage is rapidly applied, then the measurement time is reduced, but the gap becomes smaller than target due to overshoot
Solution Approach 1:
The patent implements preliminary action by pre-applying voltage in controlled stages to position the movable substrate at the target gap distance before the actual measurement begins. This ensures precise gap positioning without overshoot, and the system is ready for immediate measurement, thereby minimizing measurement time while maintaining high positioning precision.
3Adaptability or versatility
If voltage is increased to reach target wavelength, then the wavelength control range is improved, but sticking occurs due to pull-in phenomenon
Solution Approach 1:
The patent applies preliminary action by gradually increasing voltage in staged increments to reach the target voltage corresponding to the desired wavelength. This gradual voltage application prevents sudden large electrostatic forces that cause pull-in phenomenon and sticking, while still achieving the full wavelength control range. The movable substrate is steadily positioned at each voltage stage, ensuring reliable measurements across the entire wavelength range.
4Speed
If voltage is rapidly changed, then the response time is improved, but temperature variation causes wavelength shifts
Solution Approach 1:
The patent implements preliminary action by applying voltage gradually in stages and maintaining each voltage level for a stabilization period before proceeding to the next voltage level. This allows the temperature to stabilize at each stage, preventing temperature-induced wavelength shifts. The system reaches the target voltage and stabilizes before measurement begins, ensuring high wavelength measurement accuracy while maintaining efficient response time.
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 approach enables stable and accurate optical measurements by preventing sticking and minimizing wavelength variations, allowing for continuous high-speed measurement of multiple samples.
Implementation Method 1
an electrostatic actuator that changes a gap dimension between the pair of reflecting films
Implementation Method 2
a Fabry-Perot interference filter including a first mirror portion and a second mirror portion opposed to each other with a gap therebetween, and a light reception element that receives light transmitted through the Fabry-Perot interference filter
Implementation Method 3
Fabry-Perot interference filter
Data Source
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AI summary
Provided is an optical measurement control program in a light detection device including: a Fabry-Perot interference filter having a pair of mirror portions facing each other via a gap, a distance between the pair of mirror portions changing according to the potential difference generated between the pair of mirror portions; and a light detector detecting light transmitted through the Fabry-Perot interference filter, the optical measurement control program causing a computer to execute a process of measuring light to be measured by acquiring an electric signal output from the light detector, the optical measurement control program causing the computer to function as: a voltage control unit controlling the potential difference generated between the pair of mirror portions to gradually increase until the potential difference reaches a set potential difference corresponding to a wavelength of the light to be measured before the acquisition of the electric signal is started; and a signal acquisition unit acquiring the electric signal in a state where the voltage control unit allows the set potential difference to be generated between the pair of mirror portions.