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Highly selective evanescent modal filter for two-mode optical fibers.
Optics Letters
|September 10, 2009
Summary
This study demonstrates an efficient evanescent directional coupler for selective fiber optic mode coupling. The device achieves over 90% coupling to the LP(11) mode while suppressing lower-order modes, enabling new all-fiber components.
Area of Science:
- Optics
- Fiber Optics
- Photonics
Background:
- Efficiently coupling light between optical fibers is crucial for developing advanced fiber optic components.
- Controlling specific light modes within fibers, such as the LP(11) mode, is essential for specialized applications.
Purpose of the Study:
- To demonstrate an evanescent directional coupler capable of selective mode coupling.
- To achieve high coupling efficiency to the LP(11) mode while suppressing other modes.
Main Methods:
- Utilizing an evanescent directional coupler architecture.
- Fabricating and testing a device for coupling between a single-mode fiber and a double-mode fiber.
Main Results:
- Achieved greater than 90% coupling efficiency to the LP(11) mode.
- Demonstrated a minimum suppression of 24 dB for the lower-order LP(01) mode.
- Confirmed the device's functionality as a modal filter.
Conclusions:
- The developed evanescent directional coupler enables efficient and selective mode coupling.
- This technology is applicable for constructing in-line all-fiber optical components, such as modal filters.
