Researchers in Israel have created a microscopic optical device that could simplify high-power laser systems. The technology efficiently merges light from dozens of semiconductor lasers into a single optical fiber while keeping energy losses extremely low.
The device uses a 3D-printed structure known as a photonic lantern. It guides light from many small lasers into one multimode fiber without degrading brightness.
Researchers say the approach could help industries that rely on powerful fiber-delivered lasers, including manufacturing, communications, and defense.
Ph.D. student Yoav Dana led the research under Professor Dan M. Marom at the Institute of Applied Physics at the Hebrew University of Jerusalem. The team collaborated with Civan Lasers, with support from the Israel Innovation Authority.
The study demonstrates a new level of miniaturization and scalability for optical beam-combining hardware used in high-power laser systems.
New photonic lantern design
Traditional photonic lanterns combine several single-mode inputs into a single multimode waveguide. However, most high-power semiconductor lasers operate in multiple spatial modes. That mismatch has long limited how efficiently engineers can combine their output.
The Hebrew University team tackled this challenge by redesigning the lantern architecture.
Their device uses a new structure called an N-MM photonic lantern. It allows multiple multimode Vertical-Cavity Surface-Emitting Laser (VCSEL) sources to feed directly into one multimode optical fiber.
The team demonstrated photonic lanterns capable of combining 7, 19, and 37 VCSEL lasers. Each laser operated across six spatial modes.
Together, the system supported up to 222 spatial modes entering a single multimode fiber.
This architecture preserves brightness while simplifying alignment requirements. Conventional relay-lens setups often degrade beam quality or require precise positioning.
The new lantern instead matches the modal capacity of the lasers and the fiber. That design keeps optical brightness intact, a critical factor for high-power laser performance.
Compact high-power scaling
The new optical device also achieves remarkable size reduction.
Researchers produced the structure using advanced 3D micro-printing. The entire photonic lantern measures less than half a millimeter in length.
Even the largest configuration remains extremely small. The 37-input device measures just 470 micrometers.
Despite its size, the lantern delivers strong efficiency.
Tests showed coupling losses as low as –0.6 decibels for the 19-input design. The 37-input version achieved losses around –0.8 decibels.
Those numbers indicate very efficient light transfer into standard 50-micrometer multimode optical fibers.
Maintaining low loss becomes critical when combining many lasers. Small inefficiencies can quickly reduce system output power.
The researchers designed an adiabatic optical transition inside the lantern. This structure gradually converts multiple few-mode inputs into one multimode fiber channel.
That transition preserves the system’s optical degrees of freedom while minimizing scattering or power loss.
The results demonstrate a scalable method for incoherent beam combining. Instead of forcing lasers to synchronize phases, the lantern simply merges their outputs efficiently.
Such capability could help engineers build more compact high-power laser systems. It may also benefit fiber-based optical communication networks and sensing technologies.
If the approach scales further, manufacturers could combine hundreds of semiconductor lasers into a single fiber channel.
That capability would dramatically increase the power delivered through fiber-based laser systems while keeping hardware compact.
The study is published in the journal Nature Communications.