A light pulse is technically empty, yet capable of carrying a trillion photons in a single burst. That is part of what makes bright squeezed vacuum, or BSV, so strange. It is formally treated as a vacuum state of light, meaning its average electric field is zero. Yet in single shots, its quantum fluctuations can swell into extremely intense pulses. In the new Technion study, researchers finally pinned down how long those individual pulses last, and the answer lands deep in the ultrafast realm: about 27.2 femtoseconds. The work, published in Optica, comes from researchers at the Technion, Israel Institute of Technology, led by Dr. Michael Krüger and Ph.D. student Yuval Kern. The team also included Prof. Oren Cohen, Prof. Pavel Sidorenko, and Prof. Ido Kaminer, with contributions from Andrei Rasputnyi of the Max Planck Institute for the Science of Light in Erlangen, Germany. Dr. Michael Krüger (left) and Ph.D. student Yuval Kern. (CREDIT: Technion) A quantum pulse with a split personality Ordinary intense laser light, described as coherent-state light, has only weak quantum fluctuations. …