Acousto-Optic Modulation on Silicon-Aluminum Nitride Hybrid-Integrated Platform for Cryogenic Applications.

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Silicon photonics is the industry standard for integrated circuits.
• Conventional tuning mechanisms (thermo-optic, plasma dispersion) limit applications like quantum computing.
• Acousto-optic (AO) modulation presents a viable alternative for advanced silicon photonic devices.

Purpose of the Study:

• To investigate an aluminum nitride-silicon hybrid platform for acousto-optic (AO) modulation.
• To enhance AO interaction using a Fabry-Perot resonant cavity.
• To demonstrate AO modulation performance under cryogenic conditions.

Main Methods:

• Fabrication of an aluminum nitride (AlN)-silicon hybrid platform.
• Integration of a Fabry-Perot resonant cavity to enhance AO interaction.
• Testing device performance at room and cryogenic temperatures.

Main Results:

• Achieved a π-phase shift voltage (Vπ) of 27.8 V and VπL of 0.55 V·cm.
• Demonstrated improved performance at cryogenic temperatures: Vπ of 16.5 V and VπL of 0.33 V·cm.
• Device fabricated using complementary metal-oxide-semiconductor (CMOS)-compatible processes.

Conclusions:

• The AlN-silicon hybrid platform enables efficient AO modulation on silicon waveguides.
• Cryogenic operation significantly enhances device performance.
• The demonstrated device is suitable for integration into next-generation photonic systems.