The science of rogue waves in optics is now over five years old, and it has emerged as an area of broad interest to researchers across the physical sciences [1]. This area of study was initiated by the pioneering measurement of Solli et al [2] when analysing supercontinuum generation in optical fibres. Their measurements, using a novel dispersive Fourier transform technique to capture high-speed events in the time domain, observed extraordinarily high amplitude peaks at certain wavelengths in the chaotic spectrum from the supercontinuum. By analogy with the extreme waves in the ocean [3], of wide interest after 1995, such high amplitude pulses were described as ‘optical rogue waves’.