Broadband four-mode (de)multiplexer based on MMI using subwavelength grating structure.

Area of Science:

• Photonics
• Optical Engineering
• Integrated Optics

Background:

• Mode-division multiplexing (MDM) is crucial for enhancing optical interconnect transmission capacity.
• Existing mode (de)multiplexers face bandwidth limitations due to waveguide dispersion.
• Subwavelength gratings (SWG) offer potential for improved optical device performance.

Purpose of the Study:

• To present a novel broadband four-mode (de)multiplexer for on-chip MDM systems.
• To overcome the bandwidth limitations of conventional mode (de)multiplexers.
• To enable significant capacity enhancement in photonic integrated circuits.

Main Methods:

• The device combines subwavelength grating (SWG) technology with beam shaping techniques.
• It utilizes SWG-based multimode interference couplers (2x2 MMI and 4x4 MMI) and passive phase shifters.
• Beam shaping is achieved through Y-junctions, mitigating wavelength sensitivity from group-velocity dispersion (GVD).

Main Results:

• The proposed (de)multiplexer demonstrates exceptional performance over a 200 nm bandwidth (1450-1650 nm).
• Insertion loss (IL) is less than 1.2 dB for all modes.
• Crosstalk (CT) is less than -19 dB for all modes.

Conclusions:

• The novel design offers a scalable solution for broadband (de)multiplexers in next-generation MDM systems.
• This technology enables significant capacity enhancement in photonic integrated circuits.
• The device effectively addresses bandwidth limitations in optical interconnects.