Abstract: Microwave photonics links impose extremely high requirements on the linearity of modulators, whereas traditional silicon-based micro-ring assisted Mach-Zehnder high linearity modulators (RAMZM) are difficult to apply on a large scale due to their small manufacturing tolerances and low integration. This article proposes a high tolerance and high integration RAMZM, which replaces conventional circular waveguides with Euler bent waveguides and achieves ultra-low insertion loss of − 0.0034 dB at a maximum bending radius of 3 µm. By coupling the micro-ring inside the Mach-Zehnder interferometer, the device area is saved by about 1×104 µm2 compared to the external micro-ring scheme. At the same time, an adjustable coupling region is introduced to extend the process tolerance of the modulator to ±18 nm. In addition, simulation results based on 1 GHz dual-tone testing show that the spurious-free dynamic range corresponding to third-order intermodulation distortion of the modulator can reach 114.66 dB⋅Hz2/3 , verifying the high linearity advantage of the proposed structure.

Key words: silicon-based high linearity modulator, microwave photonics, Euler bent waveguide, third-order intermodulation distortion