Low-loss ZnO optical waveguides for SAW-AO applications.

Area of Science:

• Materials Science
• Optoelectronics
• Physics

Background:

• Acoustooptic Bragg deflectors (ABDs) are crucial components in optical systems.
• High diffraction efficiency is a key performance metric for ABDs.
• Zinc oxide (ZnO) is a promising material for optoelectronic devices due to its unique properties.

Purpose of the Study:

• To fabricate high-efficiency acoustooptic Bragg deflectors (ABDs) using ZnO thin films.
• To evaluate the performance of ZnO-based ABDs on different substrates (sapphire, glass, Si).
• To investigate the impact of interdigital transducer design and surface acoustic wave propagation on diffraction efficiency.

Main Methods:

• Deposition of ZnO thin films using radio frequency (RF) magnetron sputtering.
• Fabrication of ABDs on sapphire, glass, and silicon substrates.
• Measurement of optical waveguide losses and diffraction efficiencies at 632.8 nm.
• Characterization of ABDs with varying interdigital transducer Q values and acoustic wave propagation directions.

Main Results:

• Achieved high diffraction efficiencies of 95% (90 mW acoustic power on glass) and 98% (80 mW acoustic power on Si).
• Observed low optical waveguide losses of approximately 0.5 dB/cm in the ZnO films.
• Determined diffraction efficiencies for ZnO films on sapphire under varied conditions.

Conclusions:

• ZnO thin films are highly effective for fabricating high-performance acoustooptic Bragg deflectors.
• The choice of substrate and transducer design significantly influences ABD performance.
• These findings highlight the potential of ZnO-based ABDs for advanced optical applications.