Ayupova, TakhminaShaimerdenova, MadinaTosi, Daniele2021-08-272021-08-272021-05-24Ayupova, T., Shaimerdenova, M., & Tosi, D. (2021). Shallow-Tapered Chirped Fiber Bragg Grating Sensors for Dual Refractive Index and Temperature Sensing. Sensors, 21(11), 3635. https://doi.org/10.3390/s211136351424-8220https://doi.org/10.3390/s21113635https://www.mdpi.com/1424-8220/21/11/3635http://nur.nu.edu.kz/handle/123456789/5712In this work, we present a gold-coated shallow-tapered chirped fiber Bragg grating (stCFBG) for dual refractive index (RI) and temperature sensing. The stCFBG has been fabricated on a 15-mm long chirped FBG, by tapering a 7.29-mm region with a waist of 39 µm. The spectral analysis shows two distinct regions: a pre-taper region, in which the stCFBG is RI-independent and can be used to detect thermal changes, and a post-taper region, in which the reflectivity increases significantly when the RI increments. We estimate the RI and thermal sensitivities as 382.83 dB/RIU and 9.893 pm/◦C, respectively. The cross-talk values are low (−1.54 × 10−3 dB/◦C and 568.1 pm/RIU), which allows an almost ideal separation between RI and thermal characteristics. The stCFBG is a compact probe, suitable for long-term and temperature-compensated biosensing and detection of chemical analytes.enAttribution-NonCommercial-ShareAlike 3.0 United StatesChirped fiber Bragg gratingType of access: Open AccessDual sensingFiber Bragg gratingsFiber tapersOptical fiber sensorsRefractive index sensorArticle