A liquid level fiber sensor based on self-imaging properties of the multimode interference in no core fiber is proposed and demonstrated.
The detected liquid level range is 50 cm by designing a height conversion device.
The sensor has the ability to discriminate different RI.
The sensitivity of liquid level sensor is 108.8 pm/mm and the precision is about 1% at the resolution of 0.1 nm of the OSA with the liquid RI of 1.4152.