Enhancing thermo-optic efficiency through inverse-designed mode-cycling topology.

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• High power consumption of thermo-optic phase shifters limits large-scale photonic integration.
• Current devices face challenges in balancing efficiency, footprint, and CMOS compatibility.

Purpose of the Study:

• Introduce and demonstrate a mode-cycling topology to enhance thermo-optic modulation efficiency.
• Reduce power requirements for on-chip photonic systems.

Main Methods:

• Sequential conversion of optical field among guided modes within the phase-shifting region.
• Utilized inverse-designed bi-directional (de)multiplexer and mode exchanger for compactness and low loss.
• Fabricated a 2x2 mode-cycling thermo-optic enhanced switch.

Main Results:

• Achieved average insertion losses of ~2.5 dB and dynamic extinction ratio >32.7 dB.
• Demonstrated a half-wave power of ~11.9 mW, nearly halving power consumption compared to conventional devices.
• Validated the mode-cycling topology's effectiveness in enhancing modulation efficiency.

Conclusions:

• The mode-cycling topology offers a scalable solution for energy-efficient and compact photonic integrated systems.
• This approach effectively multiplies light-matter interaction without increasing device footprint.
• Experimental results confirm the potential for widespread adoption in advanced photonic applications.