This 1-T1/T2 will be minimized when T1~T2, not likely when both are maximum. I want to do the optimization in such a way that T1 and T2 would maximum corresponds to two wavelengths and transmission corresponding to other wavelengths will be a minimum. The actual goal is to build a structure that supports resonance for two wavelengths. 


Sometime after optimization, I get diverged FOM; there is no saturation value. Should I go for more generation?