Optical fiber-tip ball resonators are inexpensive devices characterized by a rapid, repeatable, and reliable fabrication process through a fiber splicer. The spectral features of a ball resonator appear as low-finesse interferometer, with an optical backscatter reflectometer (OBR) interrogator. The spectrum changes in amplitude when the external refractive index (RI) varies. In this work, we present a polarization-sensitive method for the detection of spectral changes in ball resonators. We achieved a sensitivity ranging from 366.6 dB/RIU to 6691.6 dB/RIU (refractive index units) on the most sensitive polarization, improving the sensitivity of a standard detection of 18.6%–47.7% without the need of any additional component.

光纤尖端球谐振器是廉价的设备，其特征在于通过光纤熔接器的快速，可重复和可靠的制造过程。球形谐振器的频谱特征表现为低精细干涉仪，带有光学背向散射反射仪（OBR）询问器。当外部折射率（RI）发生变化时，光谱的振幅也会发生变化。在这项工作中，我们提出了一种极化敏感方法，用于检测球谐振器中的光谱变化。我们在最敏感的偏振上实现了从366.6 dB / RIU到6691.6 dB / RIU（折光率单位）的灵敏度，无需任何其他组件就将标准检测的灵敏度提高了18.6％–47.7％。