Solution concentration and refractive index sensing based on polymer microfiber knot resonator

Abstract

We report a simple and highly sensitive solution concentration and refractive index (RI) sensor based on a microfiber knot resonator (MKR). The sensor was assembled using a flexible poly(trimethylene terephthalate) microfiber of 1.3 µm diameter. The resonance peak shifts due to the variation of the concentration of the ambient medium surrounding the MKR were detected. In the mass concentration range of 0.6–1.2%, the concentration sensitivity and resolution of the sensor are 1.7 nm/% and 1.2 × 10−3%, respectively. The highest measured sensitivity of the sensor is about 95.5 nm/RIU (RI unit) and the RI detection limit is about 2.1 × 10−5 in the RI range from 1.39 to 1.41.

Effect of titanium dioxide (TiO2) nanoparticle coating on the detection performance of microfiber knot resonator sensors for relative humidity measurement

“…6 Light travelling inside the loop of the knot resonator (in an approximately circular shape) creates an evanescent field at the outer surface that can be used for very effective sensing purposes. It offers many advantages 1 -such as high resonance quality-factor (Q-factor), low-loss and a faster and more reliable response, in terms of resonance wavelength shifting and transmitted output power variation.…”

Metal wire waveguide based all plasmonic refractive index sensor for terahertz frequencies

“…Liquids are extensively used as solvents both in laboratory as well as industry. Their refractive index is a strong function of their molar concentration [7], chemical composition etc. The high refractive index sensitivity of the sensor can thus be exploited to detect minuscule variations in these parameters.…”

High Sensitive Z-Shaped Fiber Interferometric Refractive Index Sensor: Simulation and Experiment

“…ecause of the advantages including small size, high sensitivity and immunity to electromagnetic interference, optical fiber sensors have been extensively investigated over the last decade for various physical and chemical sensing applications, such as temperature, vibration, stress and refractive index (RI) [1][2][3][4][5][6]. Particularly, the RI measurement is an important process in many fields, e.g., the detection of solution concentration in chemical field [7], real-time monitoring of antigen-antibody recognition in biological field [8] and water quality control in environmental field [9].…”