Transmission properties of tapered optical fibres: Simulations and experimental measurements
Transmission properties of tapered optical fibres: Simulations and experimental measurements
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DOI：
10.1016/j.yofte.2021.102632
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发表时间：
2021-07-24
影响因子：
2.7
通讯作者：
Buisset, Christophe
中科院分区：
文献类型：
--
作者：
Choochalerm, Piyamas;Martin, William E.;Buisset, Christophe
我们测量了锥形和非锥形光纤的传输作为输入光束的数值孔径在635 nm的函数。锥形光纤是用绝热锥形化工艺从具有50 μ m芯直径的渐变和阶跃折射率光纤制成的，以形成具有5：1锥形比的100 mm长的锥形。我们测试了锥形渐变折射率和阶跃折射率光纤制造的商业Thorlabs的产品和定制的渐变折射率锥度。5：1锥形渐变折射率光纤可以为Thorlabs提供大于0.4的传输，为定制锥形提供大于0.6的传输。我们模拟了锥形光纤的传输，并发现在感兴趣的数值孔径范围内与测量的渐变折射率锥形光纤结果合理一致。实验上，阶跃折射率锥形光纤表现相对较差，大大低于建模预期。根据我们的检查，这是因为阶跃折射率光纤的特性对锥形过程不稳健。适当地锥形渐变折射率光纤可以提供用于光纤信号的有效焦比减小的新途径，例如，在光纤光谱仪中，尽管我们强调我们的测量在这项工作中仅限于单色光。
We measured the transmission of tapered and untapered optical fibres as a function of input beam numerical aperture at 635 nm. The tapered fibres were fabricated with an adiabatic tapering process from graded and step index fibres with 50 mu m core diameters to form a 100 mm long taper with 5:1 taper ratio. We tested tapered graded-index and step-index fibres fabricated from commercial Thorlabs products and a custom graded-index taper. The 5:1 tapered graded-index fibre can give a transmission greater than 0.4 for Thorlabs and 0.6 for the custom taper. We simulated the transmission of the tapered fibres and found reasonable agreement with the measured graded-index tapered fibre results across the numerical aperture range of interest. Experimentally, step-index tapered fibres performed relative poorly and considerably below modelling expectations. Based on our examinations this arises because the properties of step-index fibre were not robust to the tapering process. Suitably tapered graded-index fibres may offer a new route for efficient focal ratio reduction of fibre optic signals, e.g., in fibre-fed spectrographs, though we stress that our measurements have been limited to monochromatic light in this work.