| 摘要 |
<p>A fiber optic sensor (10) for simultaneously and independently measuring temperature and axial stress includes a polarized light source (80) and a detector assembly (90) connected to a Mach-Zehnder device (20), which includes a pair of polarization-maintaining fibers (30, 40) that have known strain and temperature response curves. A coupling region (50) is formed between the polarization-maintaining fibers for evanescent coupling of the fibers. Each polarization-maintaining fiber (30, 40) has a plurality of fiber segments (32, 34, 36, 42, 44, 46) in which the elliptical cores are rotated 45 degrees relative to the core of the preceding segment. A segment (34, 44) from each fiber is disposed in an environment (100) to be measured. A phase shift induced by temperature or stress in each of the fibers is detected, and the strain and temperature are derived from the detected phase shift. The fiber optic sensor is capable of dual operation as both a temperature sensor and an axial stress sensor.</p> |
