Broadband phase shifter based on SiN-MoS 2 integrated racetrack resonator.

As the critical device of microwave photonics and optical communication, the low-loss and high-efficiency optical phase shifter has attracted intense attention in photonic integrated circuits. However, most of their applications are restricted to a particular band. Little is known about the characteristics of broadband. In this paper, an SiN-MoS ₂ integrated broadband racetrack phase shifter is demonstrated. The coupling region and the structure of the racetrack resonator are elaborately designed to improve the coupling efficiency at each resonance wavelength. The ionic liquid is introduced to form a capacitor structure. Then, the effective index of the hybrid waveguide can be efficiently tuned by adjusting the bias voltage. We achieve a phase shifter with a tunable range covering all the WDM bands and even up to 1900 nm. The highest phase tuning efficiency is measured to be 72.75 pm/V at 1860 nm, and the corresponding half-wave-voltage-length product is calculated as 0.0608 V·cm.