Induced Superfluorescence and the Nature of the Wave-Particle Duality

Abstract

It is now possible in practice to observe macroscopic fluctuations in the time domain initiated by an isolated single spontaneous atomic emission of light. This is the socalled “superfluorescence effect (SF)” described in some recent papers.¹ SF produces radiation pulses with much larger amplitude than predicted for normal incoherent radiation processes. The phenomenon is similar to the so-called “laser effect,” because the coherent decay of something like 108 atoms is triggered by a single spontaneous emission due to quantum fluctuations of the electromagnetic field in vacuum. This phenomenon, first detected in 1973,² has been observed in a number of near-infrared, infrared, and optical transitions,³ Atomic cesium is used for studying SF from a pencilshaped volume of active atoms. The SF emission from the pencil goes mainly through its end-faces into two narrow solid angles ?Ω. The emitted light pulse reaches a peak intensity proportional to N² (where N is the number of excited atoms) at the so-called “delay time” t_D ~ (t_R/4) (1n N)², witht_R = t_n/ (N?Ω/4π). The emitted field behaves a classical coherent field. It has a well-defined amplitude and phase: SF emission pulses from two different samples with slightly different SF transmission frequencies produce beats. Experiment confirms that the strength of the initiating quantum noise determines the average delay time.⁴ SF is set off by the first photon emitted spontaneously in the solid angle ?Ω and yields as predicted by theory a relative standard deviation in the delay time of 12% for N = 10⁸ excited atoms.