Thank you for your response.


I am interested in the transmission spectrum of the resonator array. I need to set autoshutoff to 10^-9 so that the transmittance spectrum looks reasonable. I use a point monitor to extract transmittance and phase, which is located 7 um away from the structure to ensure that I have a plane wave at the location of the point monitor. My operating wavelength is 1550 nm. 

I will try the suggestions in the link to see whether I can reduce the simulation time.