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Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
Published on: August 5, 2013
Microwave photonic filter based on circulating a cladding mode in a fiber ring resonator.
Zhu Wang1, Kin Seng Chiang, Qing Liu
1Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China.
Optics Letters
|March 3, 2010
Summary
We developed a novel microwave photonic filter using a fiber ring resonator and long-period fiber gratings (LPFGs). This compact device offers tunable frequency spacing and notch depth for advanced optical filtering applications.
Area of Science:
- Photonics
- Optical Engineering
- Fiber Optics
Background:
- Microwave photonic filters are crucial for signal processing.
- Existing filters often face limitations in tunability and compactness.
- Fiber ring resonators offer potential for integrated photonic devices.
Purpose of the Study:
- To propose and demonstrate a novel, compact, and tunable microwave photonic filter.
- To utilize cladding mode resonance in a fiber ring resonator for filtering.
- To leverage long-period fiber gratings (LPFGs) for mode coupling and wavelength selection.
Main Methods:
- Circulating a cladding mode within a fiber ring resonator.
- Injecting and extracting the cladding mode using a pair of matched LPFGs.
- Utilizing standard single-mode fiber and CO(2) laser-written LPFGs.
Main Results:
- Demonstrated a compact filter configuration.
- Achieved easily tunable frequency spacing and notch depth.
- Exhibited a frequency spacing of approximately 1.3 GHz and a notch depth of approximately 17 dB.
- Experimental results showed good agreement with theoretical calculations.
Conclusions:
- The proposed LPFG-based fiber ring resonator filter is effective and tunable.
- This approach offers a compact solution for microwave photonic filtering.
- The LPFGs provide wavelength selection and tuning capabilities, enhancing filter versatility.
