Thermo-optic Effects on Three Waveguide Directional Couplers

We studied the thermo-optic effects in detuned antisymmetric three waveguide directional couplers analytically, we analyzed the effects on switching operation on several temperature changes, which cause different switching characteristics, especially the value of propagation constant mismatch. Based on this research, it concluded that the system with three identical waveguides in which the beam launched into middle waveguide is better system to withstand cross state condition in higher temperature. Note that the system's limit changes of propagation constant mismatch in which could hold the cross state performance Delta beta = -0.4 - 0.4 before heated, Delta beta = -1.4 - 1.4 after heated 10(circle)C and Delta beta = -2.7 - 2.7 after heated 20(circle)C.