An advanced method is developed for calculating the threshold gain and lasing frequency charteristics in distributed feedback (DFB) semiconductor laser with absorption modulator.
It is a Transfer Matrix Method with an efficient algorithm of Look up Table; Look up Table can deal with the changes of almost all the paramters, and Transfer Matrix Method based on Effective Index Method is a Qusi-3 Dimensonal simulation having sufficient accuracy in any other applications.
It is found that High reflection(HR) coated DFB laser structure with large coupling coefficient $\kappa$ shows lower frequency chirping against state change of integrated modulator.
