Inverse design of polymer-based polarization-insensitive wavelength demultiplexers

Area of Science:

• Photonics
• Materials Science
• Optical Communications

Background:

• Optical communication systems face challenges due to unpredictable light polarization in network fibers.
• Polarization-independent wavelength demultiplexing is crucial for reliable optical data transmission.

Purpose of the Study:

• To develop high-performance polarization-insensitive wavelength demultiplexers (PIWDMs) using polymer materials.
• To optimize PIWDM design through topology optimization and refractive index tuning for O-band and C-band operation.

Main Methods:

• Combined polymer refractive index tunability with topology optimization-based inverse design.
• Investigated polymer refractive index of 1.7 for optimal mode confinement and minimal scattering loss.
• Analyzed fabrication tolerances to ensure device robustness.

Main Results:

• Developed two- and four-channel PIWDMs with insertion loss (IL) below 1.48 dB and crosstalk (CT) under -17.28 dB.
• Achieved polarization-dependent loss (PDL) below 0.32 dB for two-channel devices and below 0.61 dB for four-channel devices.
• Demonstrated device robustness within a -10 to +20 nm fabrication error range.

Conclusions:

• The optimized polymer refractive index of 1.7 is ideal for polymer-based PIWDMs.
• The developed PIWDMs provide an efficient and manufacturable solution for integrated photonic systems.
• These devices address the need for polarization-independent operation in optical communications.