We demonstrate a simple method for fabricating polymer end-capped fiber optic sensors with highly reproducible features. The polymer used for the devices is polydimethylsiloxane (PDMS) deposited on the cleaved end of a standard single-mode fiber forming a fiber-optic Fabry-Pérot interferometer (FFPI). Deposition is done by immersing the fiber tip into pre-cured PDMS at a prescribed velocity set by the viscosity and surface tension of the polymer. This speed-controlled dip-coating process, along with the pre-curing conditions for the PDMS, yield fiber devices with similar dimensions and spectral features. We demonstrate this upon evaluating the spectral response of the FFPIs throughout the different stages of the fabrication process; the variations in the resulting cavity lengths are estimated to be within 30 nm. The performance of the FFPI sensors for measuring the refractive index of different liquids is evaluated showing that consistent measurements are effectively achievable. Finally, we demonstrate that the spectral features of the FFPIs provide a means to account for temperature effects on refractive index measurements.

中文翻译：

---

聚合物封端光纤传感器的受控制造

我们演示了一种简单的方法来制造具有高度可重复功能的聚合物封端光纤传感器。用于设备的聚合物是聚二甲基硅氧烷（PDMS），沉积在形成光纤法布里-珀罗干涉仪（FFPI）的标准单模光纤的开裂端上。沉积是通过将纤维尖端以聚合物的粘度和表面张力设定的规定速度浸入预固化的PDMS中来完成的。这种速度可控的浸涂工艺以及PDMS的预固化条件，可生产出具有相似尺寸和光谱特征的光纤设备。我们通过评估FFPI在整个制造过程的不同阶段的光谱响应来证明这一点。结果腔长度的变化估计在30 nm以内。评估了FFPI传感器用于测量不同液体的折射率的性能，表明可以有效地实现一致的测量。最后，我们证明FFPI的光谱特征提供了一种手段来解决温度对折射率测量的影响。