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Updated: Jul 20, 2025

Author Spotlight: Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-Pérot Etalon
Published on: February 3, 2023
Fabry-Perot Interferometer Used to Measure Very Low Static Pressure Measurements
Sergio Calixto1, Roberto Zitzumbo2, Zacarías Malacara Hernandez1
1Centro de Investigaciones en Óptica, Loma del Bosque 115, Leon 37150, Mexico.
Abstract:
This paper describes the use of an optical instrument, the Fabry-Perot interferometer, adapted to measure very low pressures. The interferometer consists of two high-reflectance flat mirrors placed one in front of another. In addition, a metallic chamber contains air or a gas. In one of the faces of the chamber, a flexible thin silicone membrane is attached and, over it, one of the mirrors is glued. The other mirror rests in a fixed mechanical mounting. Light crosses both mirrors and, when it leaves them, forms an interference pattern consisting of concentric circular fringes. When the pressure is increased/decreased within the chamber, a displacement of the fringes is observed due to the movement of the glued mirror. By measuring the fringe displacement and knowing the pressure, a calibration plot can be made. Minimum pressure measurements of about tens of Pascals were achieved.
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