Mid Sweden University

An intensity modulated fiber-optic position sensor, based on a fiber to bundle coupling and a readout system using a CMOS image camera together with fast routines for position extraction and calibration, is experimentally demonstrated. Further a simulation of the complete sensor system setup is made, and possible sources of error are analyzed experimentally. Our analysis indicates the theoretical limit of the system and identifies the causes of system errors. The results are encouraging for further development of the system setup.

The modulation function for fiber-optic sensors based on coupling between fiber ends is studied for different fiber types and fiber configurations, including multiple fiber passes. Sensitivity aspects are evaluated experimentally and theoretically. It is shown that multiple passes in reality do not result in a significant sensitivity increase due to coupling losses related to fiber alignment and reflection loss.

A numerical model for evaluation of a position sensor based on a single- to multicore fiber coupling and a real-time processing CMOS camera chip is presented, allowing design of sub-µm resolution, high dynamic range sensors.

The modulation function for fiber-optic sensors based on coupling between fiber ends is studied for different fiber configurations. Sensitivity aspects are evaluated experimentally and theoretically, being shown that multiple passes practically do not increase sensitivity.