Imperial College London

Emeritus Professor SirPeterKnight

Faculty of Natural SciencesDepartment of Physics

Senior Research Investigator



+44 (0)20 7594 7727p.knight Website




206Blackett LaboratorySouth Kensington Campus





I am a theoretical physicist who has worked mainly on the quantum properties of the electromagnetic field and its interaction with atomic systems. My field of study is termed quantum optics and is shaped for the most part by the properties of laser light.

Optics before the laser was concerned entirely with the production, manipulation and detection of noise. The light which our eyes receives from natural processes is wildly fluctuating in amplitude and phase, reflecting the chaotic, random environment which gave birth to these photons. Each atom in a natural light source is excited independently. Once excited, an atom emits radiation in two ways, either spontaneously or by stimulated emission, induced by the surrounding radiation. In the natural world outside the laboratory, photons are spontaneously emitted and are completely uncorrelated in phase with any of their neighbours. In a laser, a cooperative phase transition is possible in which a collective, ordered light field is established. Quantum optics is concerned with the nature of optical correlations, the description of coherence and the properties of photons and their interaction with atoms. Laser light can be extraordinarily intense and is responsible for dramatic nonlinearities, which are exploited in important new optical technologies (long distance communications, ultrafast optical logic, isotope separation and many more). But the subject also is concerned with fundamental and generic ideas of theoretical physics: quantum coherence, nonlinearities and phase transitions from disorder to order.


EPSRC Quantum Information Processing IRC
EPSRC grant (Scheel)

EPSRC Network (Kim)
EPSRC Network (Vourdas)
EPSRC Strong Fields
RCUK Basic Technology Grant (attoseconds)