Broadband and low-cross talk mode multiplexer based on subwavelength-assisted phase matching

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Telecommunications

Background:

• Integrated mode multiplexers are essential for increasing data density in photonic networks.
• Asymmetric directional couplers are widely used due to low loss and scalability, but require bandwidth improvements.

Purpose of the Study:

• To demonstrate a multiplexer/demultiplexer link with enhanced bandwidth using subwavelength grating metamaterials.
• To achieve low loss and crosstalk over a broad operational bandwidth in a compact form factor.

Main Methods:

• Integration of asymmetric directional couplers with subwavelength grating metamaterials.
• Utilizing subwavelength-assisted phase matching for enhanced optical performance.
• Experimental characterization of the multiplexer/demultiplexer link performance.

Main Results:

• Achieved a broad operational bandwidth of 170 nm (1500 nm to 1670 nm).
• Experimental measurements demonstrated insertion losses below 0.8 dB.
• Exhibited crosstalk levels below -19.8 dB for the full link.

Conclusions:

• Subwavelength grating metamaterials effectively enhance asymmetric directional couplers for multiplexing.
• The demonstrated technology offers a compact, broad-bandwidth solution for photonic networks.
• This approach promises significant improvements in optical communication system performance.