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Abrupt coupling between strongly dissimilar waveguides with 100% transmission.
André Kurs1, John D Joannopoulos, Marin Soljačić
1Department of Physics, Massachusetts Institute of Technology, Massachusetts 02139, USA. akurs@alum.mit.edu
Optics Express
|July 13, 2011
Summary
We demonstrate a method using coupled-mode theory to perfectly join dissimilar photonic crystal waveguides. This technique efficiently couples cavity modes to waveguides, simplifying computations for high-transmission transitions.
Area of Science:
- Photonics
- Optical Engineering
- Materials Science
Background:
- Photonic crystal waveguides are crucial for integrated optics.
- Joining dissimilar waveguides with high transmission remains a challenge.
- Existing methods often involve complex designs and fabrication.
Purpose of the Study:
- To develop a systematic method for joining dissimilar photonic crystal waveguides.
- To achieve 100% transmission across the waveguide interface.
- To simplify the design and computation for such transitions.
Main Methods:
- Numerical experiments based on coupled-mode theory.
- Tuning the coupling of a cavity mode's evanescent tail to waveguides.
- Designing short transition regions (few lattice spacings).
Main Results:
- Achieved 100% transmission between very dissimilar photonic crystal waveguides.
- Demonstrated the effectiveness of tuning cavity mode coupling.
- Showcased the method's simplicity with minimal parameter tuning.
Conclusions:
- Coupled-mode theory offers a systematic approach for efficient waveguide joining.
- The proposed technique simplifies the design of high-transmission photonic interfaces.
- This method has potential for advanced integrated photonic devices.
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