Instituto de Óptica, CSIC, C/Serrano 121, 28006 Madrid, Spain.
Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid, Spain.
Sensors (Basel). 2018 Jun 10;18(6):1895. doi: 10.3390/s18061895.
In this paper we propose and demonstrate two alternative methods for the high-precision calibration of fiber Bragg grating (FBG) interrogators. The first method is based on the direct comparison between the wavelength measurements of the interrogator under test and a calibrated wavemeter, while analyzing a simulated symmetric Bragg grating constructed by a tunable filter and a fiber mirror. This first method is applicable to most commercial systems but presents an uncertainty limited by the spectral width and the wavelength stability of the tunable filter. The second method consists in measuring multiple reference absorption lines of calibrated absorption gas cells. This second method presents lower uncertainties, limited only by the optical resolution of the interrogator and the wavelength uncertainty of the reference cell absorption lines. However, it imposes more restrictive requirements on the interrogator software. Both methods were experimentally demonstrated by calibrating multiple commercial systems, reaching uncertainties down to 0.63 pm at a central wavelength of 1550 nm.
在本文中，我们提出并验证了两种用于高精度校准光纤布拉格光栅（FBG） interrogator 的替代方法。第一种方法基于在测试中的 interrogator 的波长测量值与校准后的波长计之间的直接比较，同时分析由可调谐滤波器和光纤镜构造的模拟对称布拉格光栅。这种方法适用于大多数商业系统，但存在不确定性，其限制由可调谐滤波器的光谱宽度和波长稳定性决定。第二种方法包括测量校准吸收气室的多个参考吸收线。这种方法具有更低的不确定性，仅受 interrogator 的光学分辨率和参考气室吸收线的波长不确定性限制。然而，它对 interrogator 软件提出了更严格的要求。两种方法都通过校准多个商业系统进行了实验验证，在 1550nm 的中心波长处达到了低至 0.63pm 的不确定性。
