Non-blocking 4x4 electro-optic silicon switch for on-chip photonic networks

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Device Fabrication

Background:

• Silicon photonics is a key technology for high-speed optical communication systems.
• Mach-Zehnder interferometer (MZI) based switches are fundamental components in optical switching networks.
• Standard CMOS compatibility is essential for cost-effective mass production of photonic integrated circuits.

Purpose of the Study:

• To present a novel 4x4 spatially non-blocking silicon optical switch.
• To demonstrate its fabrication using standard CMOS-compatible processes.
• To validate its performance for high-speed optical data transmission.

Main Methods:

• Fabrication of a 4x4 Mach-Zehnder interferometer (MZI) based optical switch using standard CMOS processes.
• Testing of all unique switch states and input-output (I/O) routing configurations.
• Characterization of crosstalk levels and spectral bandwidth.
• High-speed 40 Gbps data transmission experiments to verify optical data integrity.

Main Results:

• Successful demonstration of operation in all 9 unique switch states and 12 I/O routing configurations.
• Worst-case crosstalk levels were measured to be below -9 dB.
• A common spectral bandwidth of 7 nm was achieved.
• Optical data integrity was verified for all input-output channels during 40 Gbps transmission.

Conclusions:

• The developed 4x4 silicon optical switch is fully compatible with standard CMOS fabrication.
• The switch exhibits excellent performance characteristics, including low crosstalk and broad spectral bandwidth.
• The device is suitable for high-speed optical communication applications, confirming its potential for integrated photonic systems.