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Guided waves in graded-index planar waveguides with nonlinear cover medium
R K Varshney1, M A Nehme, R Srivastava
1University of Florida, Department of Electrical Engineering, Gainesville, Florida 32611, USA.
Applied Optics
|November 1, 1986
Summary
Dispersion relations for TE modes in graded-index waveguides were numerically solved. The study found lower threshold power is needed to shift the field maximum into the cover compared to step-index waveguides.
Area of Science:
- Optics and Photonics
- Waveguide Theory
- Nonlinear Optics
Background:
- Planar waveguides are crucial in integrated optics.
- Understanding mode behavior in nonlinear optical materials is essential for device design.
- Exponentially graded-index profiles offer different characteristics than traditional step-index profiles.
Purpose of the Study:
- To numerically solve dispersion relations for TE modes in a planar exponentially graded-index waveguide.
- To investigate the effect of self-focusing nonlinear cover material on mode behavior.
- To compare the threshold power requirements with step-index waveguides and experimental data.
Main Methods:
- Numerical solution of dispersion relations for Transverse Electric (TE) modes.
- Analysis of field distribution and threshold power in a graded-index waveguide.
- Comparison with theoretical and experimental results for step-index waveguides.
Main Results:
- The threshold power to pull the field maximum out of the film into the cover is lower for graded-index waveguides than for step-index waveguides.
- Numerical results show good agreement with existing experimental data.
- Empirical relations for minimum film thickness and threshold power for the lowest-order mode were derived.
Conclusions:
- Exponentially graded-index waveguides offer advantages in terms of lower threshold power for nonlinear optical applications.
- The findings provide valuable insights for designing and optimizing nonlinear optical waveguide devices.
- The derived empirical relations can simplify the design process for specific waveguide parameters.
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