Ayupova Takhmina, Shaimerdenova Madina, Tosi Daniele
School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan 010000, Kazakhstan.
Laboratory of Biosensors and Bioinstruments, National Laboratory Astana, Nur-Sultan 010000, Kazakhstan.
Sensors (Basel). 2021 May 24;21(11):3635. doi: 10.3390/s21113635.
In 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 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.
在这项工作中，我们展示了一种用于双折射率（RI）和温度传感的镀金浅锥形啁啾光纤布拉格光栅（stCFBG）。该stCFBG是在一个15毫米长的啁啾光纤光栅上制作的，通过对一个7.29毫米长、腰部直径为39微米的区域进行锥形处理。光谱分析显示出两个不同的区域：一个是锥形前区域，在该区域stCFBG与折射率无关，可用于检测热变化；另一个是锥形后区域，当折射率增加时，该区域的反射率会显著增加。我们估计折射率和热灵敏度分别为382.83 dB/RIU和9.893 pm/°C。串扰值很低（-1.54×10 dB/°C和568.1 pm/RIU），这使得折射率和热特性之间几乎能实现理想的分离。该stCFBG是一种紧凑的探头，适用于长期和温度补偿的生物传感以及化学分析物的检测。
