On-chip 7 GHz acousto-optic modulators for visible wavelengths

Area of Science:

• Photonics and Materials Science
• Quantum Technologies

Background:

• Acousto-optic modulators are crucial for light manipulation.
• Developing compact and stable modulators for visible light is challenging.
• Integration with quantum platforms requires efficient, high-frequency devices.

Purpose of the Study:

• To develop a chip-integrated acousto-optic phase modulator optimized for visible wavelengths.
• To leverage the lithium niobate on sapphire platform for enhanced device performance.
• To explore high-frequency acoustic wave interactions for advanced modulation behaviors.

Main Methods:

• Fabrication of a compact (200 micrometers) modulator on a lithium niobate on sapphire platform.
• Excitation of a 7 GHz surface acoustic wave using an interdigital transducer, aligned perpendicular to the waveguide.
• Characterization of phase modulation efficiency and single-sideband modulation behaviors at visible wavelengths.

Main Results:

• Achieved efficient phase modulation of visible light in a compact device.
• Demonstrated high stability due to a simple, unsuspended structure, facilitating easy fabrication.
• Observed pronounced single-sideband modulation, indicative of phase delay effects in acousto-optic interactions at high frequencies.

Conclusions:

• The developed acousto-optic phase modulator is suitable for visible light applications.
• The device's performance highlights the significance of phase delay effects in acousto-optic interactions.
• This technology presents new opportunities for visible photonic devices and integration with quantum platforms, including atom and ion-based systems.