The table above shows varying MZI lengths and potential group indices for the corner analysis. For example, the column titled ng1 has the group index of 4.26, row 1 for ng1 has a delta L value of 100, row 2 has a delta value of 200. Thus for the 3rd row of the column ng3, the group index is 4.17, the length difference of the MZI is 300 and the FSR is 1.920463629.