Fiber-to-chip light coupling using a graded-index (GRIN) fiber collimator is investigated. Our experiments with grating couplers and strip waveguides fabricated in a photonic integrated circuit technology reveal that the peak coupling efficiency of a GRIN fiber collimator is 7.8 dB lower than that of a single-mode fiber. However, the 3-dB alignment tolerance is improved by a factor of about 5.7 giving rise to pluggable sensor solutions. This work opens a path toward a cost-effective and portable sensor platform based on pluggable photonic biosensors using GRIN fiber collimators.

中文翻译：

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使用渐变折射率透镜光纤准直仪的光纤到芯片的光耦合

研究了使用梯度折射率（GRIN）光纤准直仪的光纤到芯片的光耦合。我们使用光子集成电路技术制造的光栅耦合器和带状波导的实验表明，GRIN光纤准直器的峰值耦合效率比单模光纤低7.8 dB。但是，3-dB对准公差提高了约5.7倍，从而产生了可插拔传感器解决方案。这项工作为使用基于GRIN光纤准直仪的可插拔光子生物传感器的低成本便携式传感器平台开辟了道路。