Force Detection Using a Fiber-Optic Cantilever

TL;DR

This paper introduces a fiber-optic cantilever-based force measurement method with high sensitivity, capable of detecting atomic-scale interactions, demonstrated through gold surface contact stiffness measurements.

Contribution

It presents a novel fiber-optic cantilever technique for highly sensitive force detection, enabling atomic-level interaction studies.

Findings

Achieved displacement detection sensitivity of 6×10^-13 m/Hz^1/2 at frequencies above 40 kHz.

Successfully measured stiffness of gold surface junctions.

Demonstrated atomic sensitivity in macroscopic force measurements.

Abstract

A force measurement technique has been developed that utilizes a clamped fiber optic element both as a cantilever and as a highly sensitive probe of the static and dynamic displacement of a sample that is mounted near its free end. Light from a 1.5 mW superluminescent diode coupled into the fiber is used to detect displacement with 6*10/sup -13 m*Hz/sup -1/2 sensitivity for frequencies above 40 kHz. This technique has been used to study the interaction between macroscopic bodies with atomic sensitivity. Here, we report measurements of stiffness of junctions that form when two gold surfaces are brought into contact.