Broadband silicon polarization beam splitter with a high extinction ratio using a triple-bent-waveguide directional...

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Silicon Photonics

Background:

• Polarization beam splitters (PBS) are essential components in optical systems.
• Achieving broadband operation with high extinction ratios (ER) and low insertion loss (IL) remains a challenge.

Purpose of the Study:

• To design and experimentally demonstrate a novel broadband silicon polarization beam splitter (PBS).
• To achieve high extinction ratios (ER) and low insertion loss (IL) over a wide operational bandwidth.

Main Methods:

• Utilized triple-bent-waveguide directional coupling in a single PBS design.
• Employed a cascaded PBS topology to enhance performance.
• Experimental demonstration using edge-coupling with a broadband light source (1520-1610 nm).

Main Results:

• Single PBS achieved ER ≥ 30 dB over 20 nm (quasi-TE) and 70 nm (quasi-TM) bandwidths.
• Cascaded PBS improved quasi-TE bandwidth to 90 nm for ER ≥ 30 dB.
• Achieved ER as high as ~42 dB with IL below 1 dB around the central wavelength.

Conclusions:

• The developed silicon PBS demonstrates superior broadband performance with high ER and low IL.
• The triple-bent-waveguide and cascaded PBS topologies are effective for enhancing PBS performance.
• This technology holds significant potential for advanced optical communication and signal processing applications.