Optimal design of a 1×4 liNbO3 optical switch based on Mach-Zehnder interferometer

A 1×4 LiNbO₃ electro-optic switch is proposed based on Mach-Zehnder interference structure. The optical switch is composed of three 1×2 MZI switch units, each of which includes Y branch, interference arm and directional coupler. The phase difference of the light propagating on two interference arms is generated through the loaded bias voltage, and the switching between the two output ports of the MZI switch unit can be realized. The parameters of Y branch and directional coupler of optical switch are designed and optimized, and the performance of the whole device is simulated. The total length of the device is 5.8cm and the insertion loss is 0.54dB. The extinction ratio bandwidth larger than 20dB reaches 100nm, and the maximum extinction ratio at the wavelength of 1550nm is 33dB. The function of optical switch with four-channel gating is realized. The proposed optical switch is expected to be used in the fields of optical interconnection and optical signal monitoring on high-speed integrated chips.