Alternative Method for HS-AFM Cantilever Displacement Sensing via the Fibre Sagnac Interferometer

Abstract

The work in this thesis has provided an alternative method of observing the displacement
of a HS-AFM cantilever while operating in contact mode. The cantilever detection system
implemented in this work is a novel form of the Sagnac interferometer that uses the
polarisation capabilities of light in its mechanism and encompasses an all-fibre system.
The HS-AFM was used in contact mode, with a fast scan frequency of 1 kHz. Images
were provided of two test subjects, namely silicon calibration grids of differing step height.
The gratings imaged were of 3 µm protruding square pitch with 20 nm step height and
of 10 µm recessed pitch with 200 nm step height.

Date of Award	9 May 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Oliver D Payton (Supervisor) & Henkjan Gersen (Supervisor)