Proton-exchanged periodically segmented waveguides in LiNbo(3)

Area of Science:

• Photonics and Waveguide Technology
• Materials Science in Optics
• Lithium Niobate Devices

Background:

• Proton-exchanged waveguides in lithium niobate are crucial for integrated optics.
• Periodically segmented waveguides offer unique optical properties.
• Understanding the influence of fabrication parameters is key for device optimization.

Purpose of the Study:

• To characterize single-mode and multimode proton-exchanged periodically segmented waveguides in lithium niobate.
• To investigate the impact of annealing time, duty cycle, and segmentation period on effective indices.
• To model the behavior of these segmented waveguides.

Main Methods:

• Fabrication of proton-exchanged periodically segmented waveguides in lithium niobate.
• Characterization of effective indices for various modes.
• Analysis of waveguide properties as a function of segmentation parameters (duty cycle, period) and annealing time.
• Development of an equivalent waveguide model.

Main Results:

• Effective indices vary with annealing time, duty cycle, and segmentation period.
• Proton-exchanged periodically segmented waveguides can be modeled as equivalent z-invariant, depth-independent graded-index waveguides with a Gaussian index distribution.
• Waveguide depth is independent of duty cycle.
• Peak refractive-index change increases linearly with duty cycle and saturates at higher values.

Conclusions:

• The characterization provides valuable insights into the optical properties of proton-exchanged periodically segmented waveguides.
• The developed equivalent waveguide model simplifies the understanding and design of these structures.
• The findings will aid in the design of advanced linear and nonlinear optical devices utilizing segmented waveguides.