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Flat top liquid crystal tunable filter using coupled Fabry-Perot cavities
Shadi A Alboon1, Robert G Lindquist
1University of Alabama in Huntsville, Huntsville, Alabama 35899, USA. alboons@eng.uah.edu
Optics Express
|June 4, 2008
Summary
This study presents a tunable liquid crystal filter with a flat top response for C and L bands. The novel tandem coupled Fabry-Perot design offers a wide tuning range and performance comparable to commercial filters.
Area of Science:
- Photonics and Optical Engineering
- Materials Science
Background:
- Fabry-Perot cavities are fundamental optical resonators.
- Liquid crystals offer tunable optical properties.
- Broadband tunable filters are crucial for optical communication.
Purpose of the Study:
- To investigate a coupled Fabry-Perot cavities filter using liquid crystal for tunable flat-top filtering.
- To achieve tunable filtering performance across the C and L bands.
- To present a tandem coupled Fabry-Perot design for a tunable passband filter with flat top and minimum ripple.
Main Methods:
- Utilizing liquid crystal as the tunable medium within coupled Fabry-Perot cavities.
- Designing a tandem coupled Fabry-Perot structure.
- Characterizing the filter's tuning range and spectral performance.
Main Results:
- Achieved tunable flat-top filtering performance across C and L bands.
- Demonstrated a tunable passband filter with minimum ripple.
- Obtained an overall tuning range of 172 nm.
- Presented designs with performance comparable to commercial 100 GHz fixed filters.
Conclusions:
- The developed liquid crystal-based coupled Fabry-Perot filter provides a viable solution for tunable broadband optical filtering.
- The tandem design effectively achieves flat-top spectral characteristics with wide tunability.
- This technology shows promise for advanced optical communication systems.
