Fast low-cost fiber-optic displacement sensor

Abstract

We have developed a fiber-optic sensor for measuring dynamic surface displacements caused by shock waves. Light from a LED emitter is sent through a plastic fiber and reflected from the surface back into the fiber. The intensity of the reflected light gives the distance to the surface. Based on simple principles and utilizing inexpensive components, micrometer and microsecond resolution is achieved at lower cost and easier usage than for interferometric methods and with better reliability than an accelerometer. The sensor is comparatively easy to set up. It is battery operated for reduced sensitivity of electromagnetic interference. The design of the fiber probe facilitates access in narrow and hostile environments.

A new hybrid catheter-tip tactile sensor with relative hardness measuring capability for use in catheter-based heart surgery

“…Using LabVIEW software, the output voltage of the photodetector is recorded by a computer. Nilsson et al [7] have proposed a similar concept to develop a displacement sensor. In the meantime, the contact force is measured by the integrated piezoresistive film.…”

Fast four-channel fibre-optic displacement sensor for measuring impact waves at low cost

“…Using optical fibres for such applications is not a new idea [8][9][10][11][12]. This paper, expanding on the work presented at OFS-17 [13], outlines how a simple yet effective and reliable fibre sensor was built at small cost. It relies on measuring the intensity of light reflected from a diffusely reflecting surface and has been used for long periods of time with excellent results.…”