Mode selecting switch using multimode interference for on-chip optical interconnects

Area of Science:

• Photonics
• Optical Communications
• Integrated Optics

Background:

• Mode-division multiplexing (MDM) is crucial for increasing optical interconnect capacity.
• On-chip optical switches are essential components for advanced optical networks.

Purpose of the Study:

• To demonstrate a novel mode selecting switch (MSS) for on-chip MDM optical interconnects.
• To evaluate the performance of the MSS in terms of switching ratio, crosstalk, switching speed, and power penalty.

Main Methods:

• Fabrication of a Mach-Zehnder interferometer-based MSS with tapered multi-mode interference couplers.
• Integration of Titanium Nitride (TiN) thermo-optic phase shifters for mode conversion and switching.
• Experimental validation using C-band operation and non-return-to-zero pseudo-random binary sequence (PRBS-31) data signals at 10 Gb/s.

Main Results:

• Achieved a switching extinction ratio greater than 25 dB and crosstalk below -12 dB.
• Demonstrated dynamic switching with a 25.8 kHz gating signal, showing switching times for both TE0 and TE1 modes below 10.9 μs.
• Observed power penalties of less than 1.7 dB at a 10^-12 bit error rate for all channels.

Conclusions:

• The demonstrated MSS is a high-performance component for on-chip MDM optical interconnects.
• The device offers efficient and fast switching between different optical modes with minimal signal degradation.
• This technology holds promise for future high-capacity optical communication systems.