Search results for "near field"
showing 5 items of 15 documents
On chip optical nanotweezing for dielectric particles manipulation
2014
On chips optical nanocavities have become useful tools for trapping and manipulation of colloidal objects. In this thesis we study the nanocavities as building blocks for optical forces, trapping and handling of particles. Proof of concept of trapping dielectric microspheres appears as the starting point of the development of lab on chip. In the first chapter we go through the literature of optical forces in free space and integrated optics. The second chapter presents the experimental tools for the characterization of nanocavities and the set-up developed to perform optical measurements with the colloidal particles. The third chapter describes the proof-of-concept trapping of polystyrene p…
Observation of Light Confinement Effects with a Near-Field Optical Microscope.
1996
This Letter reports the experimental observation of light confinement effects by near-field optical microscopy. Depolarization effects giving rise to light confinement close to nanoscopic objects have been unambiguously observed in near-field optical images of subwavelength dielectric pads etched on a flat glass substrate. According to the incident polarization, this phenomenon leads to reverse contrasts in the near-field optical image of the same subwavelength objects.
Study of a Novel High Permeability Ferrite Sheet Intended for Near Field Communication Systems
2019
The reduction of embedded portable devices involves a magnetic field interference problem when it integrates Near Field Communication (NFC) due to the presence of conductive surfaces such as ground planes, batteries or metallic enclosures. This contribution is focused on analyzing the ability of an innovative magnetic shielding based on flexible sintered ferrite sheets (FSFS) with the aim of improving the performance of that kind of systems. Thereby, a NFC emitter antenna is characterized when it is close to a conductive surface through an electromagnetic (EM) scanner. The EM scanner composed by a matrix of near field probes that make it possible to determine the effectiveness of the FSFS. …
Examining Consumers’ Usage Intention of Contactless Payment Systems
2019
Purpose The purpose of this paper is to develop and test a conceptual model that combines the modified Unified Theory of Acceptance and Use of Technology (UTAUT2) with a consumer brand engagement (CBE) model to predict consumers’ usage intentions toward contactless payment systems in a developed country. Design/methodology/approach The authors cooperated with a contactless payment service provider in Finland and reached out to 22,000 customers, resulting in 1,165 usable responses. The collected data were analyzed using structural equation modeling. Findings The study shows that the UTAUT2 and the CBE model together explain approximately 70 percent of the variance in usage intention. Of the…
Etude en champ proche et champ lointain de surfaces métalliques : apport des microscopies à sonde locale à l'étude des étalons de masse
2005
Among the international system of units (SI) the kilogram is the only one which is still defined by a material artefact, the international prototype of the platinum iridium kilogram. The instability of mass standards is one of the major concerns of national metrology institutes and the subject of numerous studies. Interest in microscopic studies of surface quality of a mass has grown, as it is well known that surface roughness is a factor in determining the long-term stability of mass standards. This thesis is devoted to the study in near field and far field for determining the topography and roughness of metallic surfaces, in related with different institute, national and international met…