fig4
Figure 4. Schematic diagram of the working principle of the MRR type TOSs. MRR based switching element with two parallel waveguides at the (A) OFF and (B) ON states, and with two cross waveguides at the (C) OFF and (D) ON states. The black arrow indicates the direction of light propagation in the waveguide-coupled resonator. MRR: Micro-ring resonator; TOSs: thermo-optic switches.
