Hitless tunable WDM transmitter using Si photonic crystal optical modulators

Area of Science:

• Photonics
• Optical Communications
• Materials Science

Background:

• Silicon photonics enables miniaturized optical devices.
• Efficient wavelength division multiplexing (WDM) transmitters are crucial for high-capacity optical networks.
• Slow light phenomena and microring resonators offer unique spectral control.

Purpose of the Study:

• To integrate novel silicon Mach-Zehnder modulators and microring multiplexers.
• To demonstrate high-speed WDM transmitter operation in a compact footprint.
• To achieve hitless wavelength tuning for robust optical communication.

Main Methods:

• Development of lattice-shifted photonic crystal waveguides for slow light.
• Design of triangular-shaped coupled-microring resonators for multiplexing.
• Integration of modulators and multiplexers onto a single chip (2.0 × 0.7 mm²).
• Demonstration of 25 Gbps/channel operation and thermo-optic tuning.

Main Results:

• Achieved compact integration of Mach-Zehnder modulators and microring multiplexers.
• Demonstrated 25 Gbps/channel operation for a WDM transmitter.
• Exhibited hitless wavelength tuning using integrated thermo-optic switches.
• Obtained box-like spectral response and wide free spectral range from microring multiplexers.

Conclusions:

• The integrated silicon photonic devices enable high-performance WDM transmitters.
• Compact size and hitless tuning capabilities are key advancements for optical communication systems.
• This work paves the way for next-generation, scalable optical transceivers.