High-performance silicon polarization switch based on a Mach-Zehnder interferometer integrated with...

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Devices

Background:

• Polarization control is crucial for optical systems.
• Existing polarization controllers often lack versatility and CMOS compatibility.
• Advanced integrated photonic devices are needed for next-generation optical communication.

Purpose of the Study:

• To propose and realize a novel CMOS-compatible polarization switch.
• To demonstrate dynamic control over polarization states and polarization extinction ratio (PER).
• To achieve efficient mode conversion and low-loss operation.

Main Methods:

• Utilized a Mach-Zehnder interferometer (MZI) integrated with polarization-dependent mode converters (PDMCs).
• PDMCs employed silicon-on-insulator (SOI) ridge waveguide tapers for adiabatic mode evolution.
• Incorporated thermally-tunable phase-shifters for electrical tuning of the MZI arms.

Main Results:

• Achieved a low excess loss of approximately 0.6 dB for TE0 and TM0 modes.
• Demonstrated dynamic tuning of polarization state and PER via electrical control.
• Obtained a measured PER of about 20 dB when the switch is activated, indicating efficient TE0-TM0 conversion.

Conclusions:

• The fabricated device functions as an effective polarization switch.
• The proposed design offers CMOS compatibility and dynamic polarization control.
• This integrated photonic device holds promise for advanced optical systems and communication.