Generating Fano resonances in the microwave domain using acousto-optic modulation on a polymer-loaded LNOI platform

Area of Science:

• Photonics
• Microwave Engineering
• Materials Science

Background:

• Microwave photonics requires efficient signal generation and processing.
• Integrated acousto-optic (AO) technology is a promising approach for microwave photonics.
• Fano resonances in integrated AO systems are underexplored.

Purpose of the Study:

• To achieve and investigate Fano resonance in the microwave domain.
• To utilize a polymer-loaded lithium niobate on insulator (LNOI) platform for AO devices.
• To enable efficient AO and electro-optic (EO) coupling for Fano resonance generation.

Main Methods:

• Design and fabrication of a photonic crystal nanobeam cavity (PCNBC).
• Integration of PCNBC with a polymer and interdigital transducer on an LNOI platform.
• Characterization of Fano resonance properties influenced by acoustic modes and radio-frequency power.

Main Results:

• Efficient AO and EO coupling achieved in a single AO modulator.
• Fano resonance demonstrated in the microwave domain.
• Tunable Fano resonance by adjusting the gap between PCNBC and interdigital transducer.
• High extinction ratio of 44 dB achieved at low radio-frequency power (-25 dBm).

Conclusions:

• The study provides a novel approach for achieving microwave Fano resonance.
• This work promotes the development of AO-based devices for microwave photonics applications.
• The demonstrated platform offers efficient microwave signal processing capabilities.