All-optical tunable buffering with coupled ultra-high Q whispering gallery mode microcavities

Area of Science:

• Photonics
• Quantum Optics
• Materials Science

Background:

• All-optical tunable buffering was previously limited by low Q factors in coupled mode induced transparency systems.
• Ultra-high Q whispering gallery mode (WGM) microcavities offer potential for longer buffering times but face challenges in dynamic tuning.
• Existing tuning methods (thermo-optic, pressure) for WGM microcavities are too slow for dynamic buffering applications.

Purpose of the Study:

• To demonstrate a novel all-optical tunable buffering system using coupled ultra-high Q WGM cavities.
• To overcome the slow tuning limitations of conventional WGM microcavities.
• To achieve significantly longer buffering times on-chip.

Main Methods:

• Utilized coupled ultra-high Q WGM cavities, specifically silica toroid microcavities, for their high Q factor (>2x10^7) and small mode volume.
• Employed the Kerr effect for instantaneous refractive index modulation, enabling rapid WGM cavity tuning.
• Integrated these components for on-chip all-optical tunable buffering operation.

Main Results:

• Achieved on-chip all-optical tunable buffering operation.
• Demonstrated a maximum buffering time of 20 nanoseconds (ns), a substantial increase from previous few hundred picoseconds (ps).
• Successfully utilized the Kerr effect for rapid tuning of the WGM cavities.

Conclusions:

• The combination of ultra-high Q WGM cavities and the Kerr effect provides an effective solution for on-chip all-optical tunable buffering.
• This approach overcomes the speed limitations of traditional tuning methods, enabling significantly enhanced buffering times.
• The developed system holds promise for future optical buffer applications requiring high speed and long delay.