Resonant coupler based on Mach-Zehnder configuration

Resonant coupler based on Mach-Zehnder configuration is one of the optical coupler that can enchance the performance of the coupling function with the advantages of low insertion loss, extremely low back reflection and precisely controllable wavelength that change only slightly with temperature. The waveguides that form the resonant coupler consists of cascaded between two directional coupler with one Mach-Zehnder configuration in the middle.