Generating synchronized, high-power laser pulses across large arrays of semiconductor lasers has long been a challenge. Traditional approaches often rely on complex external controls, making it difficult to scale these systems for real-world applications.

A new study from researchers at CREOL, the College of Optics and Photonics, offers a different, possibly a simpler solution. The team discovered that carefully engineering small differences in the operating frequencies of individual lasers allows large arrays to naturally produce synchronized, high-power and high frequency pulse trains without requiring extensive external modulation. The findings could help advance future photonic chips, optical communications, beam combining, and neuromorphic computing technologies.

The research was conducted by CREOL researchers Olivier Spitz, Greggory Scranton, Arindam Mishra, and Yehuda Braiman, in collaboration with Kendall Golden and Igor Belykh from Georgia State University. Together, the team combined expertise in photonics and nonlinear dynamics to uncover a previously unrecognized mechanism that enables networks of semiconductor lasers to spontaneously generate coherent ultrafast pulse trains.

CREOL Professor Yehuda Braiman explains how the team’s approach differs from conventional laser systems:

“Most high-power laser systems generate pulses by actively modulating the laser or by introducing specialized optical components such as saturable absorbers. In contrast, we demonstrate that large arrays of continuously driven semiconductor lasers can spontaneously organize into coherent trains of ultrafast pulses through mutual coupling in the network of lasers. Rather than suppressing differences between individual lasers, we intentionally engineer small frequency variations that enable the array to self-organize into collective dynamical states. This transforms disorder from an undesirable imperfection into a design parameter for controlling coherent optical behavior. More broadly, the work introduces a new paradigm in which large photonic networks are viewed as programmable systems capable of exhibiting emergent collective phenomena analogous to those found in condensed matter and biological systems.”

The research was published in Laser & Photonics Reviews, one of the leading journals in optics and photonics. The paper, “Coherent Multi-Pulsing Induced by Engineered Heterogeneity in Diode Laser Arrays,” highlights a promising new direction for designing scalable, high-performance laser systems.

Read the full paper to learn more about the team’s latest research.