Asymmetrical sampling structure to improve the single-longitudinal-mode property based on...

Area of Science:

• Optics and Photonics
• Semiconductor Lasers
• Nanophotonics

Background:

• Sampled Bragg grating semiconductor lasers are key for optical communications.
• Side mode oscillations degrade laser performance and limit applications.
• Achieving stable single-longitudinal mode (SLM) operation is a persistent challenge.

Purpose of the Study:

• To propose and validate a novel asymmetric sampling structure for suppressing side mode oscillations.
• To enhance the single-longitudinal mode (SLM) oscillation capability of sampled Bragg grating semiconductor lasers.
• To provide a method for fabricating high-performance, wideband multiwavelength laser arrays.

Main Methods:

• Utilizing reconstruction-equivalent-chirp technology within an asymmetric sampling structure.
• Performing numerical simulations to analyze laser mode behavior.
• Evaluating the normalized threshold gain margin and side-mode suppression ratio (SMSR).

Main Results:

• The proposed structure effectively suppresses side mode oscillations in the zeroth channel.
• A normalized threshold gain margin greater than 0.3 is guaranteed between main and side modes.
• High side-mode suppression ratios (SMSR) are achieved, confirming improved SLM performance.

Conclusions:

• The asymmetric sampling structure is a highly effective method for improving SLM operation in semiconductor lasers.
• This technique is vital for developing advanced laser arrays for telecommunications and sensing.
• The proposed approach offers a pathway to high-performance, wideband, and stable multiwavelength laser sources.