Physical origin of twice threshold phenomena in the transmission of the nonlinear photonic crystal molecules

We investigate the dynamics response of photonic crystal (PC) molecules with Kerr nonlinearity to the input continuous wave (CW) and focus on the jump action of the transmission on the input power density with the theoretical analyses and the simulation which is based on the finite-difference time-domain technique. It is found that the twice transmission jump behaviors exist when the frequency of input CW source be reasonable chosen and the photonic crystal (PC) atoms have the nearly same resonant frequency and different size. Therefore, these kinds of PC molecules can be employed to build new type optical diodes.