Search results for " and optics"
showing 10 items of 4468 documents
Roadmap on optical rogue waves and extreme events
2016
Nail Akhmediev et al. ; 38 págs.; 28 figs.
Surface plasmon resonance signal enhancement based on erlotinib loaded magnetic nanoparticles for evaluation of its interaction with human lung cance…
2021
Abstract Surface plasmon resonance (SPR) sensor provides a very useful tool based on its label-free, real-time monitoring and low price properties. However, measurement of small molecules and extremely diluted analytes is difficult and therefore, signal enhancement is required. In the present study, signal enhancement of erlotinib conjugated magnetic nanoparticles (erlotinib-MNPs) compared to erlotinib was evaluated via their interaction with overexpressed epidermal growth factor receptor on human lung cancer cells (A549 cell line) surface using SPR sensor at three temperature levels. The attained results showed an average signal amplification of about 2.5-fold for MNP-erlotinib interaction…
Casimir-Lifshitz force out of thermal equilibrium between dielectric gratings
2014
We calculate the Casimir-Lifshitz pressure in a system consisting of two different 1D dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier Modal Method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between non-equilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can…
Large numbers of cold positronium atoms created in laser-selected Rydberg states using resonant charge exchange
2016
Lasers are used to control the production of highly excited positronium atoms (Ps*). The laser light excites Cs atoms to Rydberg states that have a large cross section for resonant charge-exchange collisions with cold trapped positrons. For each trial with 30 million trapped positrons, more than 700 000 of the created Ps* have trajectories near the axis of the apparatus, and are detected using Stark ionization. This number of Ps* is 500 times higher than realized in an earlier proof-of-principle demonstration (2004 Phys. Lett. B 597 257). A second charge exchange of these near-axis Ps* with trapped antiprotons could be used to produce cold antihydrogen, and this antihydrogen production is e…
Fundamentals of 3D imaging and displays: a tutorial on integral imaging, light-field, and plenoptic systems
2018
There has been great interest in researching and implementing effective technologies for the capture, processing, and display of 3D images. This broad interest is evidenced by widespread international research and activities on 3D technologies. There is a large number of journal and conference papers on 3D systems, as well as research and development efforts in government, industry, and academia on this topic for broad applications including entertainment, manufacturing, security and defense, and biomedical applications. Among these technologies, integral imaging is a promising approach for its ability to work with polychromatic scenes and under incoherent or ambient light for scenarios fro…
Fast and blister-free irradiation conditions for cross-linking of PMMA induced by 2MeV protons
2013
For soft lithography, the conventional negative tone resists, such as SU-8, that are used to create the mold have a number of drawbacks. PMMA, which is normally used as a positive tone resist, can be used as a negative resist by using high-fluence irradiation conditions. In this report, we outline optimization of the irradiation conditions for PMMA thin films using 2MeV H^+ ions to exploit their ability to work as a negative tone resist at ion fluences above 1.0x10^1^5ionscm^-^2. The main aim was to induce cross-linking while maintaining the exposed regions free of blisters and maintaining short irradiation times. We found that by using a two-step process with a low-flux irradiation, follow…
Absolute measurement of quadratic nonlinearities from phase-matched second-harmonic generation in a single KTP crystal cut as a sphere
1997
We determine within an accuracy of ∼10% the absolute magnitude of the quadratic effective coefficients of types I and II phase-matched second-harmonic generation from conversion efficiency measurements in a single nonlinear crystal cut as a sphere. The agreement is good with measurements performed in thin parallelepipedal samples. The material studied is KTiOPO4, for which improved Sellmeier equations are given.
Sound conversion phenomena at the free surface of liquid helium. I. Calculation of the coefficients of reflection, transmission, and transformation o…
1980
On the basis of a set of boundary conditions describing quite generally mass and energy transport processes across the free surface of helium II, the acoustic coefficients of reflection, transmission, and transformation of first sound, second sound, and the sound wave propagating in the vapor are calculated in the case of perpendicular incidence of sound waves against the liquid-vapor phase boundary. Considering rigorously the influences of the Onsager surface coefficients, the isobaric thermal expansion coefficients, and the thermal conductivities of the liquid and the vapor, we derive sets of equations from which the acoustic coefficients are determined numerically. For estimations, simpl…
The vibrational levels of methane obtained from analyses of high-resolution spectra
2006
International audience; Methane and its tetrahedral isotopologues are spherical-top molecules whose high-resolution rovibrational spectra can only be analyzed in detail, thanks to sophisticated symmetry-adapted tensorial models. However, the effective Hamiltonian parameters of such models do not give direct access to the positions of the vibrational sublevels. In this paper, we present a calculation of the vibrational level positions for 12CH4, 13CH4, 12CD4 and 13CD4 performed using the effective Hamiltonian parameters obtained through recent analyses. We also include the results of a re-analysis of the octad system of 12CH4 performed with a higher order of the development which slightly im…
Photophysical behavior of 3-methylquinoline and 3-bromoquinoline
1992
Abstract The phosphorescence emission and excitation spectra and their polarizations have been studied for 3-methylquinoline and 3-bromoquinoline in methylcyclohexane and ethanol glasses at 77 K. From the results obtained in 3-methylquinoline (τp = 1.30 s in ethanol, τp = 1.05 s in methylcyclohexane and the out-of-plane polarization) it is concluded that the emission originates from a triplet state of 3ππ∗ character. In 3-bromoquinoline, the phosphorescence lifetimes (ca. 8 ms in a non-polar solvent and 15 ms in a polar solvent) and the negative degree of polarization indicate an emitting state of ππ∗ character that is strongly coupled to a higher-lying triplet state of the nπ∗ type. The mo…