All-fiber wavelength- and mode-selective coupler for optical interconnections

Area of Science:

• Optical Engineering
• Telecommunications
• Materials Science

Background:

• Standard single-mode fibers (SMF) face limitations in high-speed data transmission due to differential mode-dispersion.
• Wavelength-division multiplexing (WDM) systems require efficient signal routing and management.

Purpose of the Study:

• To demonstrate a wavelength- and mode-selective optical fiber coupler.
• To enable efficient routing of different wavelength signals for distinct communication applications.
• To reduce differential mode-dispersion penalties in gigabit ethernet links.

Main Methods:

• Experimental fabrication of a coupler utilizing intermodal coupling between SMF and hollow optical fiber (HOF).
• Characterization of device performance, including insertion loss, channel isolation, and mode-conversion efficiency.
• Demonstration of selective signal routing at 1.3-micrometer and 1.5-micrometer wavelengths.

Main Results:

• A coupler successfully directed 1.3-micrometer signals to the HOF port, converting the LP(01) mode to a ring-shaped mode.
• 1.5-micrometer signals remained in the LP(01) mode of the SMF arm.
• The device showed potential for reducing differential mode-dispersion penalties for gigabit ethernet.

Conclusions:

• The developed coupler offers selective routing of optical signals based on wavelength and fiber type.
• This technology can improve performance in both gigabit ethernet and conventional WDM systems.
• Further characterization of insertion loss, channel isolation, and mode-conversion efficiency is crucial.