150 Gbps THz Chipscale Topological Photonic Diplexer

Area of Science:

• Photonics
• Quantum Physics
• Electrical Engineering

Background:

• Photonic diplexers are crucial for high-speed on-chip communication.
• Efficiently dividing the spectrum into non-overlapping sub-bands for frequency-selective channels remains a challenge.

Purpose of the Study:

• To report an on-chip topological diplexer for terahertz frequency band filtering.
• To demonstrate high-speed data transfer using topological edge modes and Klein tunneling.

Main Methods:

• Fabrication of a silicon topological diplexer chip.
• Utilizing Klein tunneling of topological edge modes for frequency filtering.
• Implementing quadrature amplitude modulation (QAM) for data transmission.

Main Results:

• Achieved two high-speed channels, each with 12.5 GHz bandwidth, at 305 and 321.6 GHz carrier frequencies.
• Demonstrated a combined diplexer capacity of 150 Gbit/s.
• Successfully suppressed interference between adjacent channels using a guard band.

Conclusions:

• Topologically protected edge modes effectively mitigate frequency-selective fading for broadband signals.
• The developed topological diplexer shows significant promise for integrated photonic applications in terahertz and telecommunications.
• Potential applications include lossless topological multiplexers, interconnects, antennas, and modulators for future wireless generations (6G and beyond).