Novel Apodized Fiber Bragg Grating Applied for Medical Sensors: Performance Investigation

Sensors play an important role in shaping and monitoring human health. Exploration of methods to use Fiber Bragg Grating (FBG) with enhanced sensitivity has attracted great interest in the field of medical research. In this paper, a novel apodization function is proposed and performance evaluation and optimization of the same have been made. A comparison was conducted between various existing apodization functions and the proposed one based on optical characteristics and sensor parameters. The results evince the implementation of the proposed apodization function for vital sign measurement. The optical characteristics considered for evaluation are Peak Resonance Reflectivity level, Side Lobes Reflectivity level and Full Width Half Maximum (FWHM). The proposed novel apodization novel function has better FWHM, which is narrower than the FWHM of uniform FBG. Sensor characteristics like a quality parameter, detection accuracy and sensitivity also show improvement. The proposed novel apodization function is demonstrated to have a better shift in wavelength in terms of temperature and pulse measurement than the existing functions. The sensitivity of the proposed apodized function is enhanced with a Poly-dimethylsiloxane coating of varying thickness, which is 6 times and 5.14 times greater than uniform Fiber Bragg grating and FBG with the proposed novel apodization function, respectively, enhancing its utilization in the field of medicine.