Continuously tunable silicon waveguide optical switched delay line based on grating-assisted contradirectional...

Area of Science:

• Photonics
• Microwave Photonics
• Integrated Optics

Background:

• Integrated optical delay lines are essential components in microwave photonic integrated circuits.
• Continuous tunability is increasingly important for advanced filtering and beamforming applications in microwave photonics.

Purpose of the Study:

• To present and experimentally demonstrate a novel integrated continuously optical tunable delay line (OTDL) chip on a silicon platform.
• To combine stepwise and fine-tuning delay mechanisms for enhanced performance.

Main Methods:

• The OTDL chip integrates a 4-bit optical switched delay line (OSDL) for stepwise delay.
• A thermally tunable delay line utilizing a grating-assisted contradirectional coupler (CDC) provides fine delay resolution.
• The OSDL and CDC modules are combined for a total delay tuning range.

Main Results:

• The integrated OTDL chip successfully demonstrates tunable delays from 0 to 160 ps.
• The combination of OSDL and CDC achieves both stepwise and high-resolution delay tuning.
• The proposed design exhibits excellent performance and scalability through module cascading.

Conclusions:

• The developed silicon-based OTDL chip offers a promising solution for continuous delay tuning in microwave photonics.
• The modular design allows for easy expansion of the maximum delay range.
• This technology supports advancements in microwave photonic filtering and beamforming.