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I have a MQW GaN LED which works well. Now I want to do VCSEL based on that device.

Problem occurs when I start to set optical transitions -> stimulated absorption and emission. DBRs has not been added to my LED, I mean, I just wanna check if the LED works if I add the stimulated emission in optical transitions.

I checked that box and entered refractive index (n) and extinction coefficient (k) for all materials. As for the excitation frequency, I tried "from study" and "user-defined", but there is always a problem. That problem also occurs in the tutorial example provided in library gan-double-heterostructure-led.mph if I add the stimulated absorption and emission directly.

Undefined variable. - Variable: freq - Geometry: geom1 - Domains: 1, 7, 13 Failed to evaluate variable. - Variable: comp1.semi.ot1.f0 - Defined as: freq Failed to evaluate variable. - Variable: comp1.semi.ot1.omega0 - Defined as: (pi(2unitradcf))comp1.semi.ot1.f0 Failed to evaluate variable. - Variable: comp1.semi.ot1.E1ve0 - Defined as: comp1.semi.ot1.Eve-((comp1.semi.ot1.mrstar((hbarconstcomp1.semi.ot1.omega0)-comp1.semi.ot1.Ege))/comp1.semi.ot1.mhstar) Failed to evaluate variable. - Variable: comp1.semi.ot1.fv0 - Defined as: 1/(1+exp((comp1.semi.ot1.E1ve0-comp1.semi.Efpe)/(comp1.semi.TlkBconst))) Failed to evaluate variable. - Variable: comp1.semi.ot1.Gstim - Defined as: (((comp1.semi.ot1.fv0-comp1.semi.ot1.fc0)((2pi)comp1.semi.ot1.Havsquaredomega0))comp1.semi.ot1.gred0)/hbarconst Failed to evaluate expression. - Expression: dvol(comp1.semi.ot1.Gstim(-econst)) Failed to evaluate Jacobian of expression. - Expression: (-econstcomp1.semi.ot1.Gstimtest(comp1.Ne))(dvol)