Abstract A new method to improve the sensitivity of a fiber-based dissolved oxygen sensor by enhancing the evanescent field on the surface of optic fiber has been proposed and verified. The finite difference beam propagation method was used to simulate the transmission of light into the fiber. According to the simulation results, the evanescent field intensities of the step type fiber and tapered fiber were analyzed. Subsequently, a tapered fiber and step type fiber were fabricated. The layer-by-layer self-assembly process was used to place the fluorescent dye onto the surface of fiber. The reversibility, stability, response time, and temperature characteristics of the tapered fiber sensor were characterized. The experimental results show that the sensor has good repeatability, stability and temperature stability, with a response time of approximately 88 s for a change in dissolved oxygen concentration from 0 to 15 mg/L. The experimental measurements showed that the sensitivity of the tapered fiber dissolved oxygen sensor is 1.3-fold higher for dissolved oxygen concentrations from 0 to 15 mg/L compared to the step type fiber device.

中文翻译：

---

用于溶解氧检测的灵敏度改进的锥形光纤传感器

摘要 提出并验证了一种通过增强光纤表面渐逝场来提高光纤基溶解氧传感器灵敏度的新方法。有限差分光束传播方法用于模拟光进入光纤的传输。根据仿真结果，对阶梯型光纤和锥形光纤的衰减场强度进行了分析。随后，制造锥形光纤和阶梯型光纤。采用逐层自组装工艺将荧光染料置于纤维表面。表征了锥形光纤传感器的可逆性、稳定性、响应时间和温度特性。实验结果表明，该传感器具有良好的重复性、稳定性和温度稳定性，对于溶解氧浓度从 0 到 15 mg/L 的变化，响应时间约为 88 秒。实验测量表明，与阶梯式光纤装置相比，锥形光纤溶解氧传感器的灵敏度对于 0 至 15 mg/L 的溶解氧浓度高 1.3 倍。