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Published on: January 7, 2019
FSR-free add-drop filter based on silicon grating-assisted contradirectional couplers
Huiye Qiu1, Guomin Jiang, Ting Hu
1Department of Information Science and Electronics Engineering, Zhejiang University, Hangzhou 310027, China.
Optics Letters
|January 4, 2013
Summary
We developed a novel add-drop filter with an unlimited free spectral range (FSR) using silicon-on-insulator waveguides. This design minimizes unwanted coupling, enabling efficient optical signal routing for advanced photonic applications.
Area of Science:
- Photonics and Optical Engineering
- Integrated Optics
- Waveguide Devices
Background:
- Add-drop filters are crucial components in optical communication systems.
- Existing filters often suffer from limited free spectral range (FSR), restricting their applicability.
- Minimizing unwanted intra-waveguide coupling is essential for high-performance optical devices.
Purpose of the Study:
- To propose and analyze a novel add-drop filter architecture.
- To achieve an unlimited free spectral range (FSR) in an optical filter.
- To enhance the performance of grating-assisted contradirectional couplers.
Main Methods:
- Utilizing silicon-on-insulator (SOI) ridge waveguides.
- Designing asymmetric grating-assisted contradirectional couplers.
- Implementing a periodically structured corrugated waveguide distanced from the input waveguide.
Main Results:
- Calculated peak reflectivity for intra-waveguide coupling below 0.1 dB.
- Calculated contradirectional coupling higher than 20 dB.
- Experimental intra-waveguide coupling of 1.8 dB and a narrow drop-port bandwidth of 0.8 nm.
Conclusions:
- The proposed asymmetric structure effectively suppresses intra-waveguide coupling.
- The device demonstrates potential for high-performance optical filtering with an unlimited FSR.
- Experimental validation confirms the feasibility of the proposed add-drop filter design.
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