A fast Green's function method for the analysis of IDT's for acousto-optical devices

Area of Science:

• Acousto-optics
• Materials Science
• Electrical Engineering

Background:

• Surface acoustic wave (SAW) interdigital transducers (IDTs) are crucial for X-Y LiNbO3 acousto-optical (A-O) devices.
• High spurious resonance in SAW IDTs can decrease A-O efficiency, posing a design challenge.

Purpose of the Study:

• To analyze X-Y LiNbO3 IDTs using a fast Green's function method (GFM).
• To investigate the impact of spurious resonance and bulk wave excitation on A-O device performance.
• To develop a model order reduction technique for efficient frequency response generation.

Main Methods:

• Detailed analysis of X-Y LiNbO3 IDTs employing a fast Green's function method (GFM).
• Inclusion of bulk terms in the Green's function to accurately assess spurious effects.
• Application of singular value decomposition (SVD) for model order reduction to accelerate frequency response computation.

Main Results:

• Numerical results for various X-Y LiNbO3 IDT configurations show good agreement with experimental data.
• A clear interpretation of spurious resonance in SAW IDTs is provided.
• Bulk wave excitation is identified as a significant factor limiting the design of efficient, wideband IDTs for A-O devices.

Conclusions:

• The developed GFM with SVD provides an efficient method for analyzing X-Y LiNbO3 IDTs.
• Understanding and mitigating spurious resonance and bulk wave excitation are critical for optimizing A-O device performance.
• This research offers insights for designing improved SAW IDTs for acousto-optical applications.