The cooling rate of soot particles after laser induced incandescence (LII) is thought to provide an estimate of the size of nanoparticles (NPs) in the engine exhaust. It is shown that cooling rate is not applicable to NPs, and instead is only a measure of the size of micron-sized particles. The problem is that the conservation of absorbed laser photon energy in NPs is subject to quantum electro...

Two-photon fluorescence polarisation and stimulated emission depletion dynamics are investigated in three high two -photon cross-section push-push polyenes: OM62, LP79 and OM77 and compared to the behaviour of a standard fluorophore (rhodamine 6G). Two-photon fluorescence anisotropy measurements (R(0) and Ω) were undertaken using picosecond time-correlated single photon counting (TCSPC). For OM...

In this work, we use Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations to study some consequences of single photon emission, known as vacuum Cherenkov radiation, and photon decay processes in cosmic and gamma rays. These processes are forbidden in a Lorentz invariant theory but allowed under the hypothesis of LIV. We show that the emission ...

We study the measurement-induced enhancement of the spontaneous decay for a two-level subsystem, wheremeasurements are treated as couplings between the excited state and an auxiliary state rather than the vonNeumann’s wave function reduction. The photon radiated in a fast decay of the atom, from the auxiliary state to the excited state, triggers a quasi-measurement, as opposed to a projectionme...

We demonstrate experimentally two-photon gain in semiconductor structures, shown previously only in dilute atomic systems. Two-photon gain is directly observed and characterized in electrically pumped room-temperature semiconductor devices, in good agreement with theory. The semiconductor structure was designed to enhance the two-photon interaction and reduce parasitic effects. The nonlinear tw...

We report a three-phase bone scintigraphy for the diagnosis of a peripheral bone lesion caused by systemic sarcoidosis. A 32-year-old man with suspected osteomyelitis of the right forefinger underwent three-phase bone scintigraphy with Tc-99m hydroxymethylene diphosphonate (HMDP) and single-photon emission computed tomography/computed tomography (SPECT/CT). The lesion was rich in blood flow acc...