Output properties of fiber optic sensor for micro-displacement measurement at 77 K and 4.2 K

Fiber optic sensors for micro-displacement measurement are applied to displacement measurement of superconductors. Output characteristics of a fiber optic sensor were measured at 77K and 4.2K. The results show that the linearity between output voltage ratio and displacement is good both at 77K and at 4.2K, and the sensitivity at 77K is higher than that at 4.2K.