Feedback tolerance of DFB laser for silicon photonics packaging

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Device Physics
• Materials Science

Background:

• Silicon photonics offers cost-effective, miniaturized optical devices.
• Optical isolators, traditionally used to prevent feedback, add cost and size.
• Understanding external feedback is crucial for isolator-free silicon photonics packaging.

Purpose of the Study:

• To investigate the impact of external optical feedback on DFB laser performance.
• To develop a theoretical model for analyzing feedback effects in silicon photonics.
• To guide optimal packaging strategies for DFB laser chips without isolators.

Main Methods:

• Coupling the dynamic transfer matrix method with a rate equation model.
• Simulating the dynamic interaction between optical fields and carriers in DFB lasers.
• Experimental validation of the theoretical model under various feedback conditions.

Main Results:

• The coupled model accurately predicts laser spectrum splitting and output intensity fluctuations.
• Results show good agreement between theoretical predictions and experimental observations.
• Identified key feedback parameters influencing DFB laser performance.

Conclusions:

• External feedback significantly affects DFB laser performance in silicon photonics.
• The developed model provides insights into isolator-free packaging challenges.
• Theoretical analysis guides the optimization of DFB laser packaging for silicon photonic integration.