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Effective-index method and coupled-mode theory for almost-periodic waveguide gratings: a comparison.
Applied Optics
|August 20, 2010
Summary
This study analyzes contradirectional propagation in active, corrugated waveguide gratings. Two methods confirm equivalence for TE-mode operation near the Bragg wavelength, validating shallow corrugation analysis.
Area of Science:
- Photonics and Waveguide Optics
- Electromagnetism and Optics
Background:
- Active waveguide gratings enable novel photonic device functionalities.
- Understanding light propagation in corrugated structures is crucial for device design.
Purpose of the Study:
- To analyze contradirectional propagation in first-order, almost-periodic, corrugated waveguide gratings.
- To demonstrate the equivalence of coupled-mode theory and a matrix technique for TE-mode operation.
Main Methods:
- Coupled-mode theory (CMT) was employed.
- A combined effective-index/impedance-matching matrix technique was utilized.
- Analytical demonstration for shallow surface corrugations.
Main Results:
- Contradirectional propagation was analyzed.
- Equivalence between CMT and the matrix technique was analytically demonstrated for TE-mode.
- The analysis focused on operation near the first-order Bragg wavelength.
Conclusions:
- The two distinct analytical techniques yield equivalent results for specific waveguide grating configurations.
- This confirms the validity of both methods for analyzing light propagation in such structures.
- Findings support the design and optimization of photonic devices utilizing corrugated waveguides.
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