Sub-femtosecond, quantum-limited timing jitter in resonant dispersive-wave emission

Resonant dispersive-wave emission in anomalous-dispersion nonlinear media is widely regarded as intrinsically noisy, owing to strong amplification of pump-laser fluctuations during ultrafast spectral broadening. Here we show that resonant dispersive-wave emission can operate at the quantum limit, producing near-1-µm radiation from a short segment of highly nonlinear fiber pumped by a sub-30-fs, 1.5-µm ultrafast laser. Through combining numerical modeling and experiment, we disentangle the respective roles of pump noise and quantum noise in the dynamics of dispersive-wave and Raman-soliton generation. We show that, when driven by a sufficiently low-noise pump and operated under optimized nonlinear-conversion conditions, dispersive-wave timing jitter approaches its quantum limit. Using a highly sensitive timing-jitter detection scheme, we observe relative timing jitter below one femtosecond, representing the first experimental demonstration sub-femtosecond, quantum-limited dispersive-wave emission.