Timing jitter reduction of silicon hybrid harmonically mode-locked ring laser using an integrated sampled-grating DBR

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Lasers
• Integrated Optics

Background:

• Super-mode noise is a critical issue in mode-locked lasers, affecting signal quality.
• Previous methods for super-mode noise suppression in ring lasers often involve spectral filters, which can be less effective or more complex.
• Silicon photonics offers a platform for integrated laser devices, but achieving high performance requires advanced designs.

Purpose of the Study:

• To propose and investigate an integrated sampled-grating silicon hybrid mode-locked ring laser.
• To enhance super-mode noise suppression at a 20-GHz repetition rate.
• To analyze the impact of sampled-grating structures on laser dynamics, phase noise, and timing jitter.

Main Methods:

• Development of a delay differential equation (DDE) model to simulate laser dynamics.
• Integration of a sampled-grating structure and a sampled-grating distributed Bragg reflector (SGDBR) into a hybrid ring laser design.
• Comparative analysis of noise suppression performance against previous long-ring structures with spectral filters.

Main Results:

• The 20-GHz harmonic regime is significantly enhanced by the inclusion of the sampled-grating structure.
• The SGDBR provides superior optical mode selectivity, leading to greater super-mode noise suppression.
• Phase noise is improved by approximately 6 dB, and timing jitter is reduced to less than one-third compared to previous works.

Conclusions:

• The proposed integrated sampled-grating silicon hybrid mode-locked ring laser effectively suppresses super-mode noise.
• This design offers a significant improvement in phase noise and timing jitter for high-repetition-rate lasers.
• The sampled-grating approach provides a more efficient and potentially more compact solution for noise reduction in integrated photonic devices.