Broadband acoustooptic deflectors: new results.

Area of Science:

• Optics and Photonics
• Materials Science
• Acoustics

Background:

• Conventional acoustooptic (AO) Bragg deflectors utilize stepped acoustic gratings for beam steering.
• Fabrication challenges and limitations exist for stepped gratings, especially at higher frequencies (>100 MHz).

Purpose of the Study:

• To describe a new broadband AO Bragg deflector employing acoustic beam steering.
• To present an alternative fabrication method using a flat transducer array.
• To analyze the bandwidth enhancement achieved by the novel design.

Main Methods:

• A flat piezoelectric transducer grating was fabricated on the AO medium.
• Interdigitated electrode configurations created spatially periodic phase variations for acoustic steering.
• Theoretical analysis was performed to predict bandwidth improvements.
• Experimental validation was conducted using lead molybdate deflectors.

Main Results:

• The new deflector design simplifies fabrication compared to stepped arrays.
• A fourfold increase in half-power bandwidth was theoretically predicted.
• Experimental results confirmed the predicted fourfold bandwidth improvement.
• Reduced acoustic power for diffraction was noted but outweighed by fabrication ease.

Conclusions:

• The novel flat transducer AO Bragg deflector offers significant bandwidth advantages.
• Simplified fabrication makes this design suitable for high-frequency applications.
• This technology advances broadband acoustooptic device capabilities.