Micro-newton strain force and temperature synchronous fiber sensor with a high Q-factor based on the quartz microbubble integrated in the capillary-taper structure

Abstract

A micro-newton strain force and temperature synchronous fiber sensor with a high Q-factor is proposed. The sensor is based on a commercial quartz microbubble (QMB, the diameter is less than 80 µm) that is attached to the end surface of the suspending taper integrated in the hollow core fiber. The multi-beam interference and long-active-length make the sensor show both high sensitivity (0.150 nm/mN) and Q-factor (1470 based on the 3dB-bandwidth). The actual detection limit of the strain force reaches about 50 µN. The UV-cured polymer between the QMB and taper improves the temperature sensitivity. The strain force and temperature can be demodulated synchronously by using band-pass filtering and sensing matrix. The sensor can have actual application in micro-newton strain force detection as its low cost and flexible structure.