Highly sensitive displacement measurement based on spectral interferometry and Vernier effect

作者：Militky J; Kadulova M; Hlubina P

来源：Optics Communications, 2016, 366: 335-339.

DOI：10.1016/j.optcom.2016.01.021

• Tandem interferometry
• Channeled spectrum
• Envelope
• Displacement
• Wavelength interrogation
• Sensitivity

A highly sensitive measurement of the displacement of an interferometer mirror based on spectral interferometry and Vernier effect is proposed and demonstrated. The displacement measurement employs two interferometers in tandem, an interferometer represented by a combination of a polarizer, a bi-refrigent quartz crystal and an analyzer, and a Michelson interferometer. In the setup the Vernier effect is generated and the resultant channeled spectrum is with the envelope which shifts with the displacement of the interferometer mirror. We analyze the new measurement method theoretically and show that the sensitivity of the displacement measurement based on the wavelength interrogation is substantially increased in comparison to a standard method with a Michelson interferometer. We also demonstrate the realization of the measurement setup in which the position of the interferometer mirror is controlled via a closed-loop piezo positioning system. Experimental results show that the displacement measurement can reach a sensitivity of 264 nm/mu m, which is substantially increased in comparison to 34 nm/mu m reached for a standard measurement.

• 出版日期2016-5-1