New tiny photonic lantern combines 222 laser modes into one fiber

Researchers at the Hebrew University of Jerusalem have developed a microscopic photonic lantern device that efficiently combines light from multiple semiconductor lasers into a single multimode optical fiber with minimal energy loss. Unlike traditional photonic lanterns that merge single-mode inputs, this new N-MM photonic lantern architecture accommodates multiple multimode Vertical-Cavity Surface-Emitting Lasers (VCSELs), each operating across several spatial modes. The team successfully demonstrated devices combining 7, 19, and 37 VCSELs, supporting up to 222 spatial modes in total, while preserving optical brightness and simplifying alignment compared to conventional relay-lens systems. The device achieves remarkable miniaturization through advanced 3D micro-printing, with the largest 37-input lantern measuring only 470 micrometers in length. It maintains high coupling efficiency with losses as low as –0.6 dB for the 19-input and –0.8 dB for the 37-input configurations, critical for sustaining high output power in combined