Ultrasensitive fiber-optic refractive index sensor based on multimode interference with fiber-loop technique

摘要

We introduced a fiber-optic sensor, based on multimode interference, in a fiber-loop technique to realize ultrasensitive refractive index measurement. The multiplied interaction of multimode interference in the fiber-loop enlarged the spectral contrast, resulting in a sensitivity several tens of times higher than that of the sensor without the fiber-loop.