Single-cycle all-fiber frequency comb

Single-cycle pulses with a deterministic carrier-envelope phase enable the study and control of light–matter interactions at sub-cycle timescale, as well efficient generation low-noise multi-octave frequency combs. However, current single-cycle light sources are difficult to implement operate, hindering their application accessibility in wider range research. In this paper, we present 100 MHz comb compact, turnkey, reliable all-silica-fiber format. This is achieved by amplifying 2 µm seed heavily doped Tm:fiber, followed cascaded self-compression yield 6.8 fs 215 kW peak power 374 mW average power. The corresponding spectrum covers more than two octaves, from below 700 up 3500 nm. Driven pump, supercontinuum 180 integrated smooth spectral amplitude between 2100 2700 nm generated directly silica fibers. To broaden applications, few-cycle extending 6 beyond 22 long-term stable created using intra-pulse difference frequency, electro-optic sampling yields comb-tooth-resolved spectra. Our work demonstrates first all-fiber configuration that generates provides practical source nonlinear optics on same timescale.