Large-mode-area all-erbium fibres have been unveiled by nLight Corp. Manufactured with proprietary direct nanoparticle deposition active fibre production technology, they are suitable for high-power, eye-safe applications at >1.5 μm. These include lidar, rangefinding, sensing, medical and directed energy. The fibres offer core absorptions of 60 to 120 dB/m at 1530 nm and low numerical apertures of <0.10, as well as cores of 20 to 70 μm and claddings from 125 to 400 μm. In combination with the company’s high-brightness pump diodes at 980 nm, they offer the potential to deliver high powers with slope efficiencies of >45 per cent.