In a groundbreaking leap for photonics and optical engineering, a team of researchers at the Hebrew University of Jerusalem has unveiled a revolutionary microscopic 3D-printed optical device capable of profoundly transforming the landscape of high-power laser systems and optical fiber communications. This innovation centers on the efficient and compact combination of light emitted from numerous multimode Vertical-Cavity Surface-Emitting Lasers (VCSELs) into a single multimode optical fiber, achieving unprecedented scalability and minimal optical loss. This novel approach promises to overcome persistent challenges in beam combining technologies and sets a new benchmark for power delivery and system miniaturization in photonic applications.
The essence of this breakthrough lies in the creation and deployment of what the researchers call a multimode photonic lantern (MM PL), a device meticulously engineered using advanced 3D-printing techniques at the microscale. Photonic lanterns traditionally serve as optical interfaces that merge several single-mode inputs into a multimode waveguide. However, this new “N-MM PL” design uniquely accommodates multiple multimode VCSEL sources simultaneously, fundamentally redefining the operational paradigm for photonic lanterns. Unlike their predecessors, these lanterns effectively multiplex dozens of multimode laser outputs while preserving brightness and ensuring highly efficient coupling to multimode fibers.
In practical terms, the team demonstrated remarkable photonic lantern variants capable of integrating the light from 7, 19, and even 37 distinct VCSEL sources. Each VCSEL exhibits complex spatial mode structures, lasing across six spatial modes, which culminates in effective support for up to 222 spatial modes within a single multimode fiber. This massive-scale multiplexing represents a formidable advancement in optical multiplexing capacity, surpassing conventional methods both in scale and efficiency and enabling far more concentrated laser arrays without the typical penalties of alignment complexity or modal mismatch.
The manufacturing process hinges on precision 3D nanoprinting, allowing the creation of devices less than half a millimeter long—a dramatic size reduction compared to conventional bulky beam combining setups. This compact form factor does not sacrifice performance; on the contrary, it delivers exceptionally low insertion losses, registering as minimal as -0.6 dB for the 19-input lantern and a mere -0.8 dB for the 37-input system. Such low losses are critical in maintaining overall system efficiency and brightness, which directly translates into higher power delivery and improved beam quality in applications spanning industrial laser machining, medical laser systems, and advanced telecommunications.
A critical challenge in previous optical beam combining technologies stemmed from coupling inefficiencies and the inability to handle multimode beams generated by high-power VCSEL arrays. Traditional photonic lanterns were intrinsically single-mode, incompatible with the multimode nature of these VCSEL sources. The research team at Hebrew University ingeniously designed an adiabatic transition within the lantern structure, facilitating a seamless and loss-minimized conversion of multiple few-mode laser outputs into a single multimode fiber. This method preserves the modal richness and brightness of the combined beam, avoiding degradation commonly associated with relay lenses or other beam shaping techniques.
The implications of this research extend deeply into optical communications, where the preservation of modal capacity and brightness is paramount for maximizing data throughput and minimizing transmission losses. Indeed, by harnessing a highly scalable, compact, and efficient photonic lantern, fiber networks could achieve significantly enhanced performance without complex infrastructure overhauls. Moreover, the technology introduces a new dimension to high-power laser systems, where managing heat dissipation and beam quality simultaneously remains a stubborn obstacle. This lantern’s ability to combine many high-power sources without sacrificing optical integrity is poised to unlock fresh industrial and research opportunities.
This advancement is the product of insightful collaboration between the Hebrew University, Civan Lasers, and financial backing from the Israel Innovation Authority. Spearheaded by Ph.D. student Yoav Dana under the mentorship of Professor Dan M. Marom, the team’s work crystallizes years of progress in integrated optics, laser physics, and additive manufacturing. The cross-disciplinary expertise allowed for an inventive fusion of theoretical design and experimental validation, culminating in a demonstrator device whose length measures only 470 micrometers—a scale few optical multiplexers can parallel.
From a technical standpoint, the device’s operation relies on precise modal matching between the multimode inputs and the multimode output fiber. Each VCSEL array emits beams composed of multiple spatial modes, which are notoriously challenging to combine without incurring modal dispersion or brightness loss. The MM photonic lantern accomplishes this by implementing an adiabatic taper geometry that gradually transforms the spatial modes’ distributions, thus preserving the spatial coherence and brightness as these modes are delicately funneled into a fiber that supports all these parallel channel modes simultaneously.
This compact lantern also significantly relaxes the alignment precision typically required for coupling multimode beams into fibers. The intricate 3D-printed waveguide structure internally redistributes the optical paths with nanometer accuracy, easing system integration complexity while enhancing robustness against environmental perturbations—an essential feature for real-world deployment in industrial and communication systems often exposed to mechanical and thermal stresses.
The significance of this achievement is not only in the scale or the compactness but also in its practical applicability. By offering a pathway to spatially multiplexed multimode lasers with minimal insertion loss and preserved brightness, the research opens avenues to scalable, high-brightness laser arrays suitable for next-generation laser manufacturing, aerospace optical systems, and secure high-capacity fiber networks. The lantern’s potential to serve as a universal interface between multimode semiconductor lasers and fibers signals a paradigm shift for photonic system design.
Looking forward, scaling this technology further could facilitate even denser laser arrays, dramatically increasing the combined optical power deliverable through fiber networks. Such scalability ensures this innovation is future-proof, accommodating ongoing trends in miniaturization and integration in photonics. Whether applied to boosting fiber optic communication bandwidth or enhancing laser machining precision, the 3D-printed multimode photonic lantern epitomizes the fusion of cutting-edge fabrication techniques with profound optical design principles.
In summary, the Hebrew University research team has presented a transformative solution to a long-standing photonics challenge: efficiently combining the output of many multimode VCSELs into a single fiber with minimal loss and preserved brightness. The microscale 3D-printed multimode photonic lantern breaks new ground in scalability, efficiency, and compactness, promising broad impacts across scientific and industrial photonics. This work illustrates the power of interdisciplinary collaboration and advanced manufacturing to redefine optical technologies for the next wave of innovation.
Subject of Research: Not applicable
Article Title: Massive-scale spatial multiplexing of multimode VCSELs with a 3D-printed photonic lantern
News Publication Date: 10-Mar-2026
Web References: 10.1038/s41467-026-70458-4
Image Credits: Ksenia Shukhin
Keywords
Photonics, Optical materials, Fiber optics, Laser systems, Physics
