Narrow-linewidth distributed feedback moiré-grating laser for high-speed optical communications

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Lasers
• Optical Communications

Background:

• Longitudinal spatial hole burning (LSHB) degrades laser performance.
• Narrow spectral linewidth is crucial for high-speed optical communications.
• Existing distributed feedback lasers face limitations in suppressing LSHB.

Purpose of the Study:

• To simulate a novel distributed feedback moiré-grating (DFM) laser.
• To investigate the DFM laser's ability to suppress LSHB.
• To evaluate improvements in spectral linewidth and dynamic modulation characteristics.

Main Methods:

• Development of a time-domain traveling wave model.
• Simulation of DFM laser characteristics, including photon distribution and linewidth.
• Comparison of DFM lasers with state-of-the-art distributed feedback lasers.

Main Results:

• The DFM laser effectively suppresses the longitudinal spatial hole burning (LSHB) effect.
• Significant improvement in spectral linewidth was observed.
• Enhanced light-current slope efficiency and modulation bandwidth were achieved.
• Multiple π-phase shifts in moiré envelope index changes contribute to performance gains.

Conclusions:

• The DFM laser design offers a promising solution for high-speed optical communication systems.
• DFM lasers provide superior performance over conventional distributed feedback lasers.
• The proposed model accurately predicts the enhanced characteristics of DFM lasers.