Real-Time Measurements, Long Tails, and Rogue Events

Daniel Solli
University of California, Los Angeles

Rare, extreme events wield tremendous influence in many systems. Natural disasters, pandemics, stock market crashes, and freak ocean waves provide striking examples. In some cases, brief, cataclysmic events may be the key factors that shape the long-term evolution of a system. In ultrafast science, extreme events and other transient phenomena are also significant. However, most conventional measurement techniques are unable to record short, non-repetitive events because they do not operate in real time. We have developed a novel technique that enables real-time spectral acquisition over sustained intervals, opening a new window onto the world of rapid, transient phenomena. Using this method, we have recently discovered optical rogue waves—rare, brief pulses of intense light analogous to freak ocean waves. Our measurements show that optical rogue waves follow probability distributions characterized by long tails: extreme events are rare, but more common than expected from Gaussian statistics. Testifying to the potential of extreme-value science for applications, we have harnessed rogue waves to produce an enhanced source of white light. Real-time measurements also hold great promise for studying dynamic processes in other contexts, including biological systems. For example, real-time interrogation has the potential to offer new insights into the mysteries of protein folding, an area of critical importance in basic science and medicine.