Wavelength division (de)multiplexing based on dispersive self-imaging.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Waveguide Technology

Background:

• Wavelength Division Multiplexing (WDM) is crucial for increasing optical communication capacity.
• Existing WDM devices face challenges in scalability and fabrication complexity.
• Self-imaging multimode interferometers offer unique dispersive properties for optical manipulation.

Purpose of the Study:

• To propose and demonstrate a new type of WDM based on self-imaging.
• To evaluate the performance of these devices in terms of channel count, crosstalk, and insertion loss.
• To assess the design and fabrication ease and platform applicability.

Main Methods:

• Theoretical proposal of WDMs utilizing self-imaging multimode interferometers.
• Experimental fabrication of proof-of-principle devices on a silicon-on-insulator platform.
• Characterization of device performance including channel count, free spectral range, crosstalk, and insertion loss.

Main Results:

• Demonstrated 4-channel WDMs with a free spectral range exceeding 90 nm.
• Achieved an average crosstalk below -20 dB for a 1 nm bandwidth.
• Obtained an insertion loss of less than 2.0 dB.
• Predicted potential for higher channel counts and narrower channel spacing.

Conclusions:

• Self-imaging multimode interferometers provide an effective platform for WDM devices.
• The demonstrated WDMs are easy to design and fabricate.
• The underlying concept is versatile and applicable to various planar waveguide platforms, offering a scalable solution for optical networks.