In the first step, you should simulate your structure "Mode Analyze" (2D), then in the "result" section, "Derived Value", add "surface integration" and add those surfaces you want to calculate the confinement in "selection" then in the expression area write "emw.normE^2" then press evaluate button. Try this section again by "emw.normE^4" expression to calculate confinement factor denominator. because the formula is exist to calculate confinement factor in Comsol is: (II(E^2 dA))^2/II(E^4 dA)
I: Integral, II: Surface Integral, dA: Surface Element
Post by farhangi.sajadhello , how we can simulated optical confinement factor in 2D waveguide? please help me.