Timing jitter from the optical spectrum in semiconductor passively mode locked lasers

Area of Science:

• Optics and Photonics
• Semiconductor Device Physics
• Laser Technology

Background:

• Passively mode-locked semiconductor lasers are crucial for high-speed optical communications.
• Understanding and quantifying timing jitter is essential for laser performance.
• Existing methods for timing jitter estimation can be complex and require specialized equipment.

Purpose of the Study:

• To develop a theoretical model for timing jitter in passively mode-locked semiconductor lasers.
• To establish an explicit relationship between timing jitter diffusion and optical linewidths.
• To experimentally validate the theoretical model using quantum-dash lasers.

Main Methods:

• Theoretical analysis of the passively mode-locked regime in semiconductor lasers.
• Derivation of an explicit expression for the timing jitter diffusion constant.
• Experimental characterization of single-section quantum-dash lasers.
• Estimation of timing jitter from optical spectra up to 130 GHz.

Main Results:

• An explicit expression relating timing jitter diffusion constant to optical linewidths was derived.
• Experimental validation of the theoretical analysis was achieved for the first time in quantum-dash lasers.
• Timing jitter was successfully estimated from optical spectra without high-speed photodetectors.

Conclusions:

• The derived theoretical expression accurately describes timing jitter in passively mode-locked semiconductor lasers.
• Quantum-dash lasers demonstrate the practical applicability of the developed theoretical framework.
• The presented method offers a simplified approach for estimating timing jitter in mode-locked lasers.