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Published on: October 20, 2011
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Confocal laser displacement sensor using a micro-machined varifocal mirror.
Applied Optics
|October 20, 2017
Summary
This study introduces a micro-machined varifocal mirror for confocal laser displacement sensors. This innovation enables faster modulation, smaller size, and lower energy consumption for precise measurements.
Area of Science:
- Optoelectronics
- Micro-electro-mechanical systems (MEMS)
Background:
- Confocal laser displacement sensors rely on focal length modulation for measurement speed and range.
- Traditional modulation mechanisms can be bulky and energy-intensive.
Purpose of the Study:
- To investigate the application of a micro-machined varifocal mirror for focal length modulation in confocal displacement sensors.
- To develop a compact, energy-efficient, and high-speed confocal sensor.
Main Methods:
- Fabrication of an electrostatically actuated varifocal mirror using single crystalline silicon.
- Integration of the varifocal mirror into a confocal laser displacement sensor setup.
- Characterization of the sensor's working distance, actuating range, and linearity.
Main Results:
- The micro-machined varifocal mirror enables faster modulation frequencies (7 kHz) and a significant actuating range (310 μm).
- The confocal sensor achieved a working distance of 31 mm.
- Excellent linearity was observed within the actuating range, with errors from -1.1% to 1.2%.
Conclusions:
- Micro-machined varifocal mirrors offer a promising solution for enhancing confocal laser displacement sensor performance.
- This technology facilitates smaller, faster, and more energy-efficient displacement sensing applications.
