High-power laser delivery with near-diffraction-limited beam quality is typically limited to tens of metres distances by nonlinearity-induced spectral broadening inside the glass core of delivery fibres. Anti-resonant hollow-core fibres offer not only orders-of-magnitude lower nonlinearity but also loss and modal purity comparable to conventional beam-delivery fibres. Using a single-mode hollow-core nested anti-resonant nodeless fibre with 0.74 dB km⁻¹ loss, we demonstrate the delivery of 1 kW of near-diffraction-limited continuous-wave laser light over a 1 km distance, with a total throughput efficiency of ~80%. From simulations, a further improvement in transmitted power or length of more than one order of magnitude should be possible in such air-filled fibres, and considerably more if the core is evacuated. This paves the way to multi-kilometre, kilowatt-scale power delivery that is potentially useful not only for future manufacturing and subsurface drilling but also for new scientific possibilities in sensing, particle acceleration and gravitational wave detection.

具有近衍射限制光束质量的高功率激光传输通常通过传输光纤的玻璃芯内的非线性引起的光谱展宽限制在数十米的距离内。抗谐振空芯光纤不仅提供数量级的低非线性度，而且提供与传统光束传输光纤相当的损耗和模态纯度。^{使用 0.74 dB km -1}的单模空芯嵌套反谐振无节点光纤损失，我们展示了在 1 km 距离内提供 1 kW 的近衍射限制连续波激光，总吞吐量效率约为 80%。从模拟中可以看出，在这种充气光纤中，传输功率或长度的进一步改进应该可能超过一个数量级，如果纤芯被抽空，则可能会大大提高。这为多公里、千瓦级的电力输送铺平了道路，不仅对未来的制造和地下钻探有用，而且对传感、粒子加速和引力波探测的新科学可能性也很有用。