Spontaneous emission

About: Spontaneous emission is a research topic. Over the lifetime, 12855 publications have been published within this topic receiving 323684 citations.

Saturation of the junction voltage in stripe‐geometry (AlGa)As double‐heterostructure junction lasers

Abstract: Saturation of the junction voltage has been observed to occur at the onset of lasing in cw stripe‐geometry (AlGa)As double‐heterostructure junction lasers. Simultaneous measurements of the nonlasing but amplified spontaneous emission confirm that saturation of the optical gain and spontaneous emission accompany the voltage saturation as expected. With well‐behaved lasers the observed saturation is maintained over currents to at least 50% above threshold. In other devices, a loss of saturation is commonly observed to occur simultaneously with a nonlinearity in the current dependence of the lasing emission.

Quantum-size effects on radiative lifetimes and relaxation of excitons in semiconductor nanostructures

Abstract: A systematic study of exciton dynamics is presented in quantum boxes formed naturally along the axis of a V-shaped quantum wire, by means of time and spatially resolved resonant photoluminescence. The dependence of radiative lifetimes and relaxation mechanisms of excitons is determined versus the size of the boxes. The radiative recombination rate varies linearly with the length of the box, showing that the exciton has a coherence volume equal to the volume of the box. In a low excitation regime, emission from excited states has not been observed, which would be a consequence of relaxation bottleneck, but there is clear evidence that relaxation via emission of LA phonons depends strongly on the energy separation between the different quantum box levels.

Single-atom cavity-enhanced absorption. I. Photon statistics in the bad-cavity limit

Abstract: The photon statistics of the transmitted light from a driven cavity containing a single resonant two-level atom are studied in the bad-cavity limit. For weak driving fields, the second-order intensity correlation function shows novel nonclassical behavior due to the interference of the driving field and forward reradiation from the atom. This behavior is related to squeezing in the cavity transmission. A physical interpretation is given in terms of the reduced quantum state of the coupled atom-field system following photodetection. >

Deterministic coupling of site-controlled quantum emitters in monolayer semiconductors to plasmonic nanocavities

Abstract: Solid-state single-quantum emitters are a crucial resource for on-chip photonic quantum technologies and require efficient cavity-emitter coupling to realize quantum networks beyond the single-node level. Previous approaches to enhance light-matter interactions rely on forming nanocavities around randomly located quantum dots or color centers but lack spatial control of the quantum emitter itself that is required for scaling. Here we demonstrate a deterministic approach to achieve Purcell-enhancement at lithographically defined locations using the sharp corner of a metal nanocube for both electric field enhancement and to deform a two-dimensional material. For a 3 by 4 array of strain-induced exciton quantum emitters formed into monolayer WSe2 we show spontaneous emission rate enhancement with Purcell-factors (FP) up to FP=1050 (average FP=272), single-photon purification, and cavity-enhanced quantum yields increasing from initially 1 % to 15 %. The utility of our nanoplasmonic platform is applicable to other 2D material, including boron nitride, opening new inroads in quantum photonics.

Experimental determination of the dynamics of a molecular nuclear wave packet via the spectra of spontaneous emission.

Abstract: The dynamics of a wave packet in the nuclear degree of freedom of a sodium dimer have been studied via the time- and frequency-resolved spectrum of spontaneous emission. This technique allows one to track the nuclear wave packet dynamics in a single excited electronic state over a substantial fraction of its periodic trajectory. The quantum beats in the spectrum may be partially interpreted in terms of the classical-like evolution of an initially random distribution of internuclear separations. We observe the expansion and contraction of the wave packet that is characteristic of a quadrature squeezed state