Cost-Effective $2\times 2$ Silicon Nitride Mach-Zehnder Interferometric (MZI) Thermo-Optic Switch

We present cost effective 2 x 2 silicon nitride Mach-Zehnder interferometric thermo-optic switches with 1 mm-length phase shifter. Devices were fabricated on a bulk silicon wafer with CMOS compatible process. The footprint was ~0.7 mm
²
. For the device designed for λ~1310 nm, we demonstrated ~26.8-dB crosstalk, 0.23-dB insertion loss, and 17.25-μs switching speed at λ~1325.8 nm. Similarly, λ~1550 nm device showed the ~24.7-dB crosstalk, 0.48-dB insertion loss, and 17.48-μs switching speed at λ~1550.8 nm. The measured operating power was 55.6 and 64.4 mW at λ~1325.8 nm and λ~1550.8 nm, respectively.