Silicon photonic broadband polarization-insensitive switch based on polarization-mode diversity conversion

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Devices

Background:

• Optical switches are fundamental components in photonic integrated circuits.
• Achieving polarization-insensitivity is a key challenge for reliable optical communication systems.
• Silicon-on-insulator (SOI) technology offers a robust platform for integrated photonics.

Purpose of the Study:

• To design and demonstrate a 2x2 polarization-insensitive optical switch.
• To achieve broadband operation with high performance metrics.
• To enable efficient polarization-division-multiplexed optical interconnects.

Main Methods:

• Utilized a balanced Mach-Zehnder interferometer (MZI) structure.
• Incorporated polarization-insensitive adiabatic couplers and thermo-optic phase shifters.
• Employed polarization rotators based on mode hybridization and evolution in wide waveguides.

Main Results:

• Achieved broadband polarization-insensitive operation from 1500 nm to 1600 nm.
• Demonstrated extinction ratios > 15 dB, insertion losses < 2.3 dB, and polarization-dependent losses < 1 dB.
• Reported a power consumption of 29.1 mW for switching both TE0 and TM0 modes.

Conclusions:

• The developed switch is a promising building block for on-chip optical interconnects.
• The design overcomes limitations of polarization-dependent losses in SOI devices.
• This technology facilitates advancements in polarization-division-multiplexing for higher data rates.