Sensor system

摘要

A sensor system (10) in an interferometric arrangement has a sensor arm (24) and a reference arm (28). The reference arm (28) is in a stable environment and the sensor arm (24) is arranged to be subject to variations in strain and/or temperature. Radiation from a broadband source (12) propagates through the arrangement and a broadband interferogram is generated as an air gap (114) is scanned. The interferogram is recorded on an oscilloscope (126) and analysed using signal processing software on a computer (128). From the analysis the changes in group delay and optical dispersion of the light in the sensor arm (24) due to strain and temperature changes is measured, and values for the strain and/or temperature changes calculated. A narrowband light source (86) may be used for accurate calibration of path length differences during scanning. The strain and temperature on the sensor arm (24) may be calibrated or tested using clamps (30, 32) and a thermal enclosure (34). The system may also be configured in a tandem interferometry arrangement (200) including a sensing interferometer (202) and reference interferometer (204).