Reviewed by Lexie CornerJun 4 2024
In a recent paper published in Light: Science & Applications, a team of researchers from the Hebrew University of Jerusalem’s Institute of Applied Physics, in collaboration with scientists from Nokia Bell Labs, developed a Free-Standing Microscale Photonic Lantern Spatial Mode (De-)Multiplexer. It was created by applying direct laser writing to the tip of an optical fiber using a 3D nano-printing technique.
The photonic lantern is engineered to losslessly convert between optical sources and modes by optimizing the converging waveguide structure using adaptive learning algorithms and optical simulations. The structure is then printed onto a multi-core fiber source using direct laser writing and two-photon polymerization techniques. Left: Fiber-tip view of ceramic ferule with embedded multi-core fiber, with 300 microns tall, 3D printed photonic lantern on the tip. Right: Magnified microscope view of photonic lantern. Image Credit: Yoav Dana
Optical waves flowing through air or multi-mode fiber can be patterned or decomposed using orthogonal spatial modes, which have a wide range of uses in imaging, communication, and directed energy. However, the systems that conduct these wavefront alterations are large, limiting their use to high-end applications.
According to recent research, the construction of a free-standing microscale photonic lantern spatial mode (de-)multiplexer utilizing 3D nanoprinting represents a significant achievement in photonic technology.
This spatial multiplexer, distinguished by its compact size, small footprint, and ability to directly print on and adhere to photonic circuits, optical fibers, and optoelectronic elements (such as lasers and photodetectors), opens up new possibilities for system integration and technology adoption in future high-capacity communication systems and complex imaging modalities.
Photonic lantern devices can convert between an array of segregated single-mode optical signals and optical waves with a superposition of modes or distorted wavefronts. The technology is a strong candidate for providing spatial division multiplexing (SDM) in optical communication networks with a large capacity in the future. It can also be utilized for imaging and other applications where spatial manipulation of optical waves is necessary.
By utilizing high-index contrast waveguides in conjunction with 3D nano-printing capabilities, the researchers have created a small, adaptable device that can be printed onto almost any solid surface with high fidelity and fine accuracy, allowing it to be seamlessly integrated into a range of technological contexts.
Integrating the approximately 100-micrometer size device with micro-scale photonic systems is exceedingly difficult because it differs significantly from standard photonic lanterns that rely on millimeter- to centimeter-long, weakly guiding waveguides.
The development of this Free-Standing Microscale Photonic Lantern Spatial Mode (De-)Multiplexer represents a significant advancement in our ability to enable and adopt spatial multiplexing for diverse optical systems and applications. This breakthrough makes space division multiplexing technology much more accessible and amenable towards integration, opening up new possibilities for optical communication and imaging applications, to name a few.
Dan Marom, Professor, Institute of Applied Physics, Hebrew University of Jerusalem
The researchers designed a 375 µm long, six-mode mixing photonic lantern that can combine six single-mode inputs into one six-mode waveguide using genetic algorithms, fabricated it onto a fiber tip, and characterized it. Despite its small size, the device has low wavelength sensitivity, low insertion loss (-2.6 dB), and low polarization and mode-dependent losses (-0.2 dB and -4.4 dB, respectively).
Journal Reference:
Dana, Y., et al. (2024) Free-standing microscale photonic lantern spatial mode (De-)multiplexer fabricated using 3D nanoprinting. Light: Science & Applications. doi:10.1038/s41377-024-01466-6