Search results for "OPTICS"
showing 10 items of 10033 documents
Dynamics of Strongly Coupled Modes between Surface Plasmon Polaritons and Photoactive Molecules: The Effect of the Stokes Shift
2017
We have investigated the dynamics of strongly coupled modes of surface plasmon polaritons (SPPs) and fluorescent molecules by analyzing their scattered emission polarization. While the scattered emission of SPPs is purely transverse magnetic (TM) polarized, the strong coupling with molecules induces transverse electric (TE) polarized emission via the partial molecular nature of the formed SPP–molecule polariton mode. We observe that the TM/TE ratio of the polariton emission follows the contribution of the molecular excited states in this hybrid mode. By using several types of molecules, we observe that, in addition to the coupling strength, which determines the contribution of the molecular…
Integration of large-area optical imagers for biometric recognition and touch in displays
2021
In recent years there has been an increasing interest to integrate optical sensing in mobile displays, for instance, for biometric fingerprint scanning functionality. There are several routes to incorporate optical fingerprint functionality within the full display area, each with their own benefits and challenges. Here we investigate the different integration routes using large-area, ultra-thin imagers based on organic photodiodes.
Clinical evaluation of automated capillary refill time estimation in dogs and cats
2019
In this study, we clinically evaluated a pulse oximeter-based device for automated capillary refill time (CRT) estimation in dogs and cats. CRT can reveal conditions like shock or anemia in dogs and cats. However, visual CRT estimation has low repeatability, and the available optical systems for automated estimation are not suitable for pets. We evaluated a custom-made portable CRT measuring device on various measurement sites of 12 dogs and 11 cats with parallel visual CRT estimation on the gum by treating veterinarian. The capillary refill was also recorded by a video camera for reference. The visual and video procedures were moderately correlated with the coefficient of 0.61; visual CRT …
Propulsion Calculated by Force and Displacement of Center of Mass in Treadmill Cross-Country Skiing
2022
This study evaluated two approaches for estimating the total propulsive force on a skier’s center of mass (COM) with double-poling (DP) and V2-skating (V2) skiing techniques. We also assessed the accuracy and the stability of each approach by changing the speed and the incline of the treadmill. A total of 10 cross-country skiers participated in this study. Force measurement bindings, pole force sensors, and an eight-camera Vicon system were used for data collection. The coefficient of multiple correlation (CMC) was calculated to evaluate the similarity between the force curves. Mean absolute force differences between the estimated values and the reference value were computed to evalua…
Dynamics and extraction of quantum discord in a multipartite open system
2011
We consider a multipartite system consisting of two noninteracting qubits each embedded in a single-mode leaky cavity, in turn connected to an external bosonic reservoir. Initially, we take the two qubits in an entangled state while the cavities and the reservoirs have zero photons. We investigate, in this six-partite quantum system, the transfer of quantum discord from the qubits to the cavities and reservoirs. We show that this transfer occurs also when the cavities are not entangled. Moreover, we discuss how quantum discord can be extracted from the cavities and transferred to distant systems by traveling leaking photons, using the input-output theory.
Spectroscopic signatures for planar equilibrium geometries in methyl-substituted oligothiophenes
2009
In recent studies it was demonstrated that temperature-dependent optical spectroscopy is a valuable tool for revealing the differences in the geometries of flexible molecules like oligothiophenes (OTs) in the ground (S0) and first excited (S1) electronic states, by examining the symmetry relations between the absorption and emission spectra: while at low temperature the spectra show mirror symmetry, pointing to planar geometries in S0 and S1, the symmetry relation breaks down at ambient temperature due to thermal population of torsional modes. In the present joint spectroscopic and theoretical study, we demonstrate that this behavior is also observed for di- and tetramethyl-substituted OTs,…
Origin of the Red Sites and Energy Transfer Rates in Single MEH-PPV Chains at Low Temperature
2011
Single poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) molecules dispersed in thin poly(methylmethacrylate) films have been investigated by fluorescence emission, excitation and time-resolved spectroscopy at 1.2 K. For the molecular weight studied (∼200 kDa) a bimodal distribution of emission maxima is observed. Based on a comparison of the spectroscopic properties of blue and red sites and on polarisation-resolved measurements, we argue in agreement with recent quantum-chemical calculations that the red subpopulation most probably does not arise from interchromophoric excitation delocalisation but is to be attributed to longer chromophoric units originating from orde…
Nonlinear Relaxation in Population Dynamics
2001
We analyze the nonlinear relaxation of a complex ecosystem composed of many interacting species. The ecological system is described by generalized Lotka-Volterra equations with a multiplicative noise. The transient dynamics is studied in the framework of the mean field theory and with random interaction between the species. We focus on the statistical properties of the asymptotic behaviour of the time integral of the i-th population and on the distribution of the population and of the local field.
<title>Refractive properties of separate erythrocytes of Chernobyl clean-up workers at different pH</title>
2000
This study is focused on the modifications in erythrocytes of Chernobyl nuclear power plant accident clean-up workers as a late health effect of short-term impact of high level radioactive contamination. As a result, a new method based on erythrocyte (RBC) refractive index properties at different pH has been elaborated. According to the light dispersion theory for fluids refractive index is associated with molecules mass m. This feature is widely used for estimation of cell dry mass. But there is another refractive index dependency from molecules charge q regardless of its sing. This feature is not being used for cell quantitative and qualitative characterization. In this study, RBC were in…
Lifetime measurements of the 3D3/2 and 3D5/2 metastable states in CaII
1993
The lifetime of the metastable 3D3/2 and 3D5/2 states of Ca+ ions is determined in a r.f. ion trap by laser excitation of this levels and subsequent time delayed probing of the state population by a second laser. In a buffer gas atmosphere of about 10−5−10−6 mbar of He we observe quenching to the ground state and strong finestructure mixing of the two D-states. This mixing allowes only the determination of the combined lifetime. Our result of τ(3D)=1.24(39) s is in good agreement with theoretical calculations.