Nanostructured fibers for sub‐10 fs optical pulse delivery

A novel fiber technology is presented that enables the transmission of 200 nm wide spectra over meter‐long distances with minimal temporal reshaping and acceptable losses down to about 3 dB/m. Delivery of a 10 fs pulse over nearly meter distance is experimentally demonstrated, which sets a new standard for the fiber‐based delivery of few‐cycle pulses. Numerical simulations provide insight into the unique guiding mechanism in the novel hollow‐core fiber technology, enabling dispersion parameters that are within an order of magnitude of those available in free space propagation.