High-performance and ultra-wide bandwidth silicon TM polarizer with suppressed reflection utilizing a tailored...

Area of Science:

• Photonics and optical engineering
• Integrated optics
• Nanophotonics

Background:

• Polarization control is crucial for optical communication systems.
• Existing TM polarizers often suffer from limited bandwidth or high insertion loss.
• Silicon-on-insulator (SOI) platforms offer advantages for integrated photonic devices.

Purpose of the Study:

• To design and demonstrate a compact TM polarizer with high polarization extinction ratio (PER), low loss, and suppressed reflection.
• To achieve ultra-wide bandwidth operation on a 220nm SOI platform.
• To improve upon previous TM polarizer designs in terms of performance and footprint.

Main Methods:

• Utilized a contra-mode conversion Bragg grating (CMC-BG) embedded in a multimode waveguide.
• Employed a sophisticated grating design with tailored chirping and apodization profiles.
• Simulated and experimentally verified the device performance.

Main Results:

• Achieved a simulated compact footprint of 34.72 × 1.22 µm².
• Demonstrated ultra-wide bandwidth of 346 nm with simulated PER > 40 dB and insertion loss (IL) < 1 dB.
• Suppressed reflection to < -15 dB across an extended bandwidth exceeding 450 nm.
• Experimentally confirmed IL < 1.2 dB and PER > 30 dB over a bandwidth of 336 nm.

Conclusions:

• The developed TM polarizer offers excellent performance metrics, including high PER, low IL, and ultra-wide bandwidth.
• The device's compact size and performance make it suitable for various integrated photonic applications.
• The CMC-BG approach provides a promising route for advanced polarization management in silicon photonics.