Highly Sensitive Current Sensor Based on an Optical Microfiber Loop Resonator Incorporating Low Index Polymer Overlay

A highly sensitive current sensor based on an optical microfiber loop resonator (MLR) incorporating low index polymer is proposed and experimentally demonstrated. The microfiber with a waist diameter of 2 μm is wrapped around the nichrome wire with low index polymer overlay to realize the MLR as the highly sensitive current sensor. Low index polymer overlay can successfully reduce round-trip fractional loss resulting in the improvement of the Q-factor (Q) and the finesse (F) of the MLR around the nichrome wire. The use of the microfiber with a waist diameter of 2 μm and low index polymer with high thermal property can effectively improve the current sensitivity of the proposed MLR to be 437.9 pm/A
²
.