Broadband polarization-insensitive optical switch on silicon-on-insulator platform

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Devices

Background:

• Optical switches are crucial components in telecommunication networks.
• Polarization sensitivity in optical switches can degrade signal quality and complicate system design.
• Silicon-on-insulator (SOI) technology offers a promising platform for integrated optical devices.

Purpose of the Study:

• To design and demonstrate a polarization-insensitive optical switch on SOI.
• To achieve high extinction ratios and low insertion losses for all optical polarizations.
• To validate the device performance through theoretical analysis and experimental measurements.

Main Methods:

• Utilizing a Mach-Zehnder interferometer (MZI) structure.
• Designing submicron waveguides and 3dB couplers for polarization independence.
• Employing a 340nm-thick top-silicon layer on SOI substrate.
• Conducting theoretical simulations and experimental characterization across the C-band.

Main Results:

• Theoretical analysis predicts extinction ratios better than -25dB and insertion losses below -0.6dB for both transverse-electric (TE) and transverse-magnetic (TM) modes.
• Experimental results confirm the polarization-insensitive operation.
• Measured extinction ratios of approximately -15dB for both polarizations were achieved.

Conclusions:

• The proposed MZI-based optical switch effectively overcomes polarization-dependent issues.
• The demonstrated device is suitable for integrated photonic applications requiring polarization-insensitive operation.
• The SOI platform enables the fabrication of high-performance polarization-insensitive optical switches.