One-dimensional polarization-independent grating couplers are demonstrated with the aid of the adaptive genetic algorithm optimization. By adjusting the relative weight between the coupling efficiency and the bandwidth of the polarization-dependent loss (PDL), we control the evolution direction and customize the final performance of the device. Two specific designs are generated by giving more weight to the coupling efficiency and the PDL bandwidth, respectively. Coupling efficiencies of the first design are measured to be ${-}{7.6}\;{\rm dB}$ and ${-}{7.9}\;{\rm dB}$ at 1550 nm for TE and TM polarizations, respectively, while its 1.0 dB PDL bandwidth is 25.0 nm. In contrast, the second design presents higher coupling efficiencies of ${-}{7.6}\;{\rm dB}$ and ${-}{7.2}\;{\rm dB}$ at 1550 nm for TE and TM polarizations, respectively. However, its 1.0 dB PDL bandwidth is 22.0 nm.

中文翻译：

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自适应遗传算法优化与偏振无关的光纤芯片光栅耦合器

借助自适应遗传算法优化，证明了一维偏振无关光栅耦合器。通过调整耦合效率和偏振相关损耗（PDL）带宽之间的相对权重，我们可以控制演进方向并定制器件的最终性能。通过分别赋予耦合效率和PDL带宽更多的权重，可以生成两个特定的设计。对于TE和TM极化，在1550 nm处测得的第一个设计的耦合效率分别为$ {-} {7.6} \; {\ rm dB} $和$ {-} {7.9} \; {\ rm dB} $，其1.0 dB PDL带宽为25.0 nm。相反，第二种设计呈现出更高的耦合效率$ {-} {7.6} \; {\ rm dB} $和在1550 nm处TE和TM偏振分别为$ {-} {7.2} \; {\ rm dB} $。但是，其1.0 dB PDL带宽为22.0 nm。