Learning Forum

[Trish]

Hi all,

I'm using the model of MQW edge laser https://support.lumerical.com/hc/en-us/articles/360041725214 but with different composition number in InGaAsP. It says

[Kyle]

When you create a new quaternary alloy material in the Electrical/Thermal database, all of the required properties for the MQW solver should be set according to the new composition using interpolation (https://support.lumerical.com/hc/en-us/articles/360034398494).
Creating quaternary materials in this way is a newer feature, you might need to update your software to use it. This should calculate all the required properties for the MQW solver, using the buildmqwmaterial command shouldn't be necessary for this step.

[Trish]

Thank you very much for your reply. I wonder if I can ask another question?
What I want to know is the refractive index change induced by current input, which is in a MQW with PN junction . So I tried to combine two models: MQW edge emitting laser and PN depletion phase shift https://support.lumerical.com/hc/en-us/articles/360042328674-PN-depletion-phase-shifter. But I just realized there is only voltage source in 'boundary condition' in CHARGE. So I want to know is it possible to add a current source?

[Kyle]

It's not possible to define a current as the electrical boundary condition in CHARGE, you will have to use the voltage. When you refer to the "refractive index change induced by current input", do you mean the index change due to the presence of charge carriers (as described on this page: https://support.lumerical.com/hc/en-us/articles/360034382494)? If so, when you perform the voltage sweep in that PN junction workflow you get the IV curve as a result. You can look at this IV curve to determine the voltage that corresponds to the current input. The charge distribution from this voltage can be imported to MODE to see the refractive index change, as demonstrated in that PN junction workflow.