2 × 2 16-ch silicon photonics wavelength-selective switch based on waveguide gratings.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Devices

Background:

• Wavelength-selective switches are crucial components in optical communication networks.
• Silicon photonics offers a scalable platform for integrated optical devices.
• Existing switches often face limitations in operational bandwidth and performance.

Purpose of the Study:

• To demonstrate a 2x2 16-channel silicon photonics wavelength-selective switch.
• To leverage contra-directional couplers and thermo-optic Mach-Zehnder switches for enhanced performance.
• To analyze the device's performance across a wide wavelength range.

Main Methods:

• Fabrication of a silicon photonics chip incorporating contra-directional couplers with sidewall corrugated Bragg gratings.
• Integration of thermo-optic Mach-Zehnder switches for wavelength selection.
• Characterization of optical performance including insertion loss, extinction ratios, and bandwidth.

Main Results:

• Achieved a fiber-to-fiber insertion loss of 9.2 dB and on-chip loss of 5.4 dB (16-channel average).
• Obtained bar-port extinction of 15.0 dB and cross-port extinction of 23.0 dB (16-channel average).
• Demonstrated operation over a wide wavelength range (C- and L-band) with a 3-dB bandwidth of 4.2 nm.

Conclusions:

• The developed silicon photonics switch offers efficient wavelength selection with competitive performance metrics.
• The use of sidewall corrugated Bragg gratings enables an unlimited free spectral range, crucial for broadband operation.
• Further improvements in spectral performance can be achieved by analyzing wavelength dependence and resonant effects.