A Compact Fiber Device Providing a Petahertz of Coherent Bandwidth

Due to their unique ability to combine high-frequency resolution with broad spectral coverage and the generation of single-cycle pulses, femtosecond frequency combs are essential in various areas of fundamental research and applied photonics. Examples are high-precision spectroscopy and sensitive experiments in the field of ultrafast phenomena. Generating such short pulses demands precise management of dispersion across a large bandwidth - a highly challenging task often requiring complex setups that can compromise stability and efficiency. To over-come these challenges, we present a device with unprecedented characteristics: A compact fiber-based laser source generating a coherent frequency comb covering a petahertz of optical bandwidth, from the deep ultraviolet (wave-length of 280 nm) to the mid-infrared (2700 nm).