Boeck Robert, Caverley Michael, Chrostowski Lukas, Jaeger Nicolas A F
Opt Express. 2015 Apr 20;23(8):10573-88. doi: 10.1364/OE.23.010573.
We present a process calibration method for designing silicon-on-insulator (SOI) contra-directional grating couplers (contra-DCs). Our method involves determining the coupling coefficients of fabricated contra-DCs by using their full-width-at-half-maximum (FWHM) bandwidths. As compared to the null method that uses the bandwidth measured at the first nulls, our FWHM method obtains more consistent results since the FWHM bandwidth is more easily determined. We also extract the coupling coefficients using curve-fitting which provide values that are in general agreement with the values obtained using our method. However, as compared to the curve-fitting method, our method does not require knowledge of the insertion loss and is easier to implement. Our method can be used to predict the FWHM bandwidths, the maximum power coupling factors, the minimum power transmission factors, and the through port group delays and dispersions of subsequent, fabricated devices, which is useful in designing filters.
我们提出了一种用于设计绝缘体上硅（SOI）反向光栅耦合器（contra-DC）的工艺校准方法。我们的方法包括通过使用其半高全宽（FWHM）带宽来确定制造的contra-DC的耦合系数。与使用在第一个零点处测量的带宽的零值法相比，我们的FWHM方法获得的结果更一致，因为FWHM带宽更容易确定。我们还使用曲线拟合来提取耦合系数，其提供的值与使用我们的方法获得的值总体上一致。然而，与曲线拟合方法相比，我们的方法不需要插入损耗的知识，并且更易于实现。我们的方法可用于预测后续制造器件的FWHM带宽、最大功率耦合因子、最小功率传输因子以及直通端口群延迟和色散，这在设计滤波器时很有用。
