Kumar Abhai, Nambiar Siddharth, Kallega Rakshitha, Ranganath Praveen, Ea Priya, Selvaraja Shankar Kumar
Opt Express. 2021 Mar 29;29(7):9699-9710. doi: 10.1364/OE.412266.
Polymer photonic circuits offer a versatile platform for various applications, including communication, sensing and optical signal processing. Though polymers offer broadband, linear and nonlinear optical properties, the coupling between an optical fibre and a polymer waveguide has been a challenge. In this work, we propose and demonstrate a wafer-scale vertical coupling scheme for polymer waveguides. The scheme uses a silicon nitride grating coupler with an inverse taper to couple between an optical fibre and a SU8 polymer waveguide. We demonstrate a maximum coupling efficiency of -3.55 dB in the C-band and -2.92 dB in the L-band with a 3-dB bandwidth of 74 and 80 nm, respectively. A detailed design and simulation, fabrication, and characterisation results are presented. The scheme demonstrates a scalable and efficient surface grating approach for polymer photonic integrated circuits.
聚合物光子电路为包括通信、传感和光信号处理在内的各种应用提供了一个通用平台。尽管聚合物具有宽带、线性和非线性光学特性，但光纤与聚合物波导之间的耦合一直是一个挑战。在这项工作中，我们提出并演示了一种用于聚合物波导的晶圆级垂直耦合方案。该方案使用具有反向锥形的氮化硅光栅耦合器在光纤和SU8聚合物波导之间进行耦合。我们展示了在C波段的最大耦合效率为-3.55 dB，在L波段为-2.92 dB，3 dB带宽分别为74和80 nm。给出了详细的设计与仿真、制造以及表征结果。该方案展示了一种用于聚合物光子集成电路的可扩展且高效的表面光栅方法。
