Dharmander Malik

Thanks for your reply. I will try to give you more detail this time so that you can understand the situation better.

  1. I have gone through the mentioned Lumerical example thoroughly. It is not clear how does the software obtain absorption spectra for AlGaAs/GaAs structures internally? Which model/equation is Lumerical using to produce the absorption spectra internally? It is quite important to understand if someone wants to use other material for QCSE design that may not be persent in the material library. 
  2. The distorted absorption spectra mean that the obtained spectra shape is not theoretically expected, like the one shown below which I obtained from InGaAs/InP QCSE simulation (the curve is somehow inverted). It may be because the default material properties for the other materials is not so well defined. 

  1. I am also looking for another possibility, such as importing the absorption spectra of a structure calculated in other software at zero bias. Then, it can be imported into Lumerical and then checked for its bias sweep dependency (QCSE behaviour in Charge). Any suggestion on how to do this?

If CHARGE only varying the absorption spectra with bias then where is the absorption spectra information at zero bias. Any lead would be a great help.