Multiwavelength semiconductor lasers facilitate industry applications

In the mid-1990s, researchers developed the first multi-wavelength lasers using semiconductors. This breakthrough was thought to be primarily useful for gas spectroscopy. Two decades on, these lasers are still predominantly used in the lab, but they are increasingly studied for innovative commercial applications, such as 6G transmissions and remote sensing.

Virte and Marin-Palomo discuss the potential of such lasers for optical signal processing, particularly for millimeter wave and sub-terahertz frequencies.

“The development of multi-wavelength lasers has opened up a lot of possible applications,” author Martin Virte said. “For example, there’s quite a bit of momentum building up behind the ideas of using lasers not just as light sources, but for other applications such as signal processors.”

The perspective summarizes different ways to fabricate multi-wavelength lasers using standard techniques and common materials, reviews the dynamics of multi-wavelength emission, and discusses their application for optical signal processing.

With the recent development of key components of multi-wavelength lasers, their use for signal processing is seemingly just around the corner, the authors wrote. And with increased commercial accessibility of these components, lasers could be built at affordable prices.

“I think it will be a matter of years — five to ten maybe — before we see new applications of multiwavelength semiconductor lasers being picked up by industry,” Virte said. “We hope that this perspective will motivate people to take the concepts of multiwavelength semiconductor lasers and look for new applications.”

While the potential is there, there remain a few hurdles for commercial development, such as improving the understanding of the dynamics of the lasers and proof-of-principle demonstrations.

Source: “Integrated multi-wavelength lasers for all-optical processing of ultra-high frequency signals,” by Martin Virte and Pablo Marin-Palomo, Applied Physics Letters (2023). The article can be accessed at https://doi.org/10.1063/5.0170499 .