12-channel LAN wavelength-division multiplexer with low random phase errors.

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Wavelength division multiplexing (WDM) is crucial for high-capacity optical communications.
• Silicon nitride (SiN) offers advantages for photonic integrated circuits due to its low thermo-optic coefficient and transparency.

Purpose of the Study:

• To demonstrate a 12-channel WDM device on a silicon nitride platform.
• To minimize random phase errors in Mach-Zehnder interferometers for improved device performance.
• To showcase the potential of silicon nitride for advanced optical communication components.

Main Methods:

• Fabrication of a 12-channel WDM using Mach-Zehnder interferometers on a 300 nm-thick silicon nitride platform.
• Detailed analysis of phase error contributors within the interferometers.
• Implementation of targeted structural optimizations to mitigate phase errors.

Main Results:

• Achieved a 70% reduction in random phase errors.
• Demonstrated excellent device performance: -0.87 dB insertion loss, -17 dB crosstalk, and 2.3 nm 1-dB bandwidth.
• Observed high fabrication tolerance (22 pm/nm) and excellent intra- and inter-chip reproducibility.
• Estimated low temperature-dependent center wavelength shift (11 pm/K) due to silicon nitride's properties.

Conclusions:

• The developed silicon nitride WDM exhibits superior performance and reproducibility.
• Structural optimizations effectively reduce phase errors, enhancing device functionality.
• This work highlights silicon nitride as a promising material for high-capacity, passive optical communication devices.