cavity quantum electrodynamics describes the behaviour of a quantum emitter inside an optical cavity, and is one of the few realizable experimental systems in which the coherent interaction between the emitter and the cavity mode can exceed dissipative and dephasing processes. Recent advances in this field include the observation of vacuum Rabi splitting1–3, interference4, upconversion5 and the...

The hypersensitive response (HR) is one mechanism of the resistance of plants to pathogen infection. It involves the generation of reactive oxygen species (ROS) which have crucial roles in signal transduction or as toxic agents leading to cell death. Often, ROS generation is accompanied by an ultraweak photon emission resulting from radical reactions that are initiated by ROS through the oxidat...

We report on three-photon excited band edge and trap emission of CdS semiconductor nanocrystals. While the band edge emission intensity clearly shows a cubic dependence on excitation intensity, demonstrating three-photon absorption process, the trap emission does not exhibit such a cubic dependence. A simple theoretical model based on the assumption that there exist a limited number of trap sta...

We update our calculations of thermal-photon production in nuclear collisions at the BNL Relativistic Heavy-Ion Collider (RHIC). Specifically, we address the recent experimental observation of an elliptic flow of direct photons comparable in magnitude to that of pions, which is at variance with expectations based on quark-gluon plasma (QGP) dominated photon radiation. Our thermal emission rate ...

We compare analytically techniques for multiplephoton coincidence imaging in terms of spatial resolution, detector efficiency (or simply efficiency), and system sensitivity for a spherical water phantom (or simply sensitivity). One analysis consists of comparing photon-photon coincidence single-photon-emission computerized tomography (PP-SPECT) with angularly unconstrained, electronically colli...

We report two-photon excited emission in borosilicate glasses doped with ZnSe nanocrystalline quantum dots. The emission, predominantly near the two-photon energy and detected in the direction of the excitation beam, is in the visible, and the fundamental excitation is the near-infrared output of a tunable femtosecond laser. Depending on the two-photon energy, timeand frequency-resolved measure...