Integrated accuracy enhancement for the Fabry-Pérot interferometer: The multi-parameter approach series (MPAS)

Area of Science:

• Physics
• Materials Science
• Surface Science

Background:

• Fabry-Pérot white light interferometry is crucial for surface force apparatus (SFA).
• Accurate characterization of optical layers, especially mica spacers, is vital for SFA's precision in measuring confined fluids.
• Mica spacer layers significantly limit the accuracy of nano-confined film measurements due to their optical path length.

Purpose of the Study:

• To develop an integrated method for in situ determination of mica thickness and dispersive refractive index.
• To enhance the absolute accuracy of SFA measurements without conventional mica-mica contact calibration.
• To improve the accuracy of sub-nanometer confined fluid property determination.

Main Methods:

• Implementation of the multi-parameter approach series (MPAS) algorithm.
• In situ determination of mica thickness and dispersive refractive index.
• Utilizing spectral correlation for accuracy enhancement.

Main Results:

• The MPAS algorithm significantly enhances the accuracy of mica parameter determination.
• The method achieves enhanced instrumental accuracy by increasing spectral correlation.
• Eliminates the need for conventional mica-mica contact calibration.

Conclusions:

• The MPAS method provides a significant accuracy enhancement for SFA instruments.
• Accurate assessment of mica's elasto- and opto-mechanical properties is necessary for future accuracy improvements.
• The study highlights the critical role of mica optical properties in SFA measurements.