High efficiency input-output prism waveguide coupler: an analysis.

Area of Science:

• Photonics and Waveguide Technology
• Integrated Optics
• Materials Science (Lithium Niobate)

Background:

• Efficient coupling of light into and out of optical waveguides is crucial for integrated photonic devices.
• Prism-based couplers are a common method, but optimizing efficiency and practicality remains an area of research.

Purpose of the Study:

• To present the theory and experimental performance of a novel prism waveguide input-output coupler.
• To demonstrate a high-efficiency coupling scheme using a single prism for both input and output.
• To evaluate the performance in a specific material system, Lithium Niobate (LiNbO3).

Main Methods:

• Theoretical modeling of the prism waveguide coupling mechanism.
• Experimental fabrication and testing of the coupler.
• Utilizing Titanium (Ti) diffused waveguides in LiNbO3 substrates.
• Measuring coupling efficiency with light propagating 1 cm within the waveguide.

Main Results:

• Achieved a high coupling efficiency of 94%.
• Demonstrated the effectiveness of a single prism for both input and output coupling.
• Validated the performance with Ti-in-diffused LiNbO3 waveguides.

Conclusions:

• The presented prism waveguide coupler offers a highly efficient solution for optical signal interfacing.
• The single-prism design simplifies device architecture while maintaining excellent performance.
• This technology holds promise for advanced integrated photonic applications.