Measuring coupling efficiency in single-mode channel waveguides: a new technique.

Area of Science:

• Optoelectronics
• Materials Science
• Photonics

Background:

• Accurate characterization of optical waveguides is crucial for device performance.
• Titanium-indiffused Lithium Niobate (LiNbO3) waveguides are widely used in integrated optics.
• Measuring coupling efficiencies and propagation losses is essential for optimizing waveguide devices.

Purpose of the Study:

• To develop and demonstrate a technique for accurately measuring input prism coupling efficiencies in single-mode channel waveguides.
• To quantify scattering and absorption losses in single-mode channel and planar diffused waveguides.
• To characterize loss parameters for both TE and TM modes in Ti-in-diffused LiNbO3 waveguides.

Main Methods:

• A novel technique was employed to measure input prism coupling efficiencies.
• Scattering and absorption losses were measured using established optical loss measurement techniques.
• Measurements were performed on Ti-in-diffused LiNbO3 waveguides with channel widths of 3 micrometers before diffusion.

Main Results:

• Input prism coupling efficiencies exceeding 1% were accurately measured.
• Propagation losses for channel waveguides were determined to be in the range of 1.34 to 1.66 dB/cm.
• Loss measurements were successfully conducted for both transverse electric (TE) and transverse magnetic (TM) modes.

Conclusions:

• The developed technique enables precise measurement of prism coupling efficiencies in single-mode waveguides.
• The study provides valuable loss data for Ti-in-diffused LiNbO3 channel and planar waveguides.
• The findings contribute to the understanding and optimization of optical waveguide performance for integrated photonic applications.