Broadband phase shifter based on SiN-MoS₂ integrated racetrack resonator

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Optical phase shifters are essential components in photonic integrated circuits for microwave photonics and optical communication.
• Existing phase shifters often have limited operational bandwidth, hindering broadband applications.
• Developing broadband, low-loss, and high-efficiency phase shifters is critical for next-generation optical technologies.

Purpose of the Study:

• To demonstrate a novel silicon nitride-molybdenum disulfide (SiN-MoS2) integrated broadband racetrack phase shifter.
• To achieve efficient tuning of optical phase over a wide wavelength range.
• To enhance coupling efficiency and device performance through elaborate design.

Main Methods:

• Fabrication of an SiN-MoS2 integrated racetrack resonator.
• Design optimization of the coupling region and resonator structure for broadband operation.
• Integration of an ionic liquid to form a capacitor structure for voltage-controlled tuning.

Main Results:

• Demonstration of a broadband phase shifter with a tunable range covering all Wavelength Division Multiplexing (WDM) bands up to 1900 nm.
• Achieved a highest phase tuning efficiency of 72.75 pm/V at 1860 nm.
• Calculated a half-wave-voltage-length product of 0.0608 V·cm, indicating high efficiency.

Conclusions:

• The demonstrated SiN-MoS2 integrated racetrack phase shifter offers broadband tunability, addressing a key limitation of current devices.
• The device shows high phase tuning efficiency and a low half-wave-voltage-length product, making it suitable for practical applications.
• This work paves the way for advanced broadband photonic integrated circuits in optical communication and signal processing.