PHUNG , Ha

The purpose of this thesis is to provide understanding of Vietnamese consumer's online behaviour. This is done through an examination of Vietnamese consumers' online behaviour regarding digital and social media, as well as factors influencing such behaviour. The framework focuses on digital marketing concepts and consumer behaviour....

It is shown that the results presented in the above letter, and attributed by the authors to amplitude-to-phase conversion in the photodetector, do not originate in the photodetector under test, due to the power dependence observed. More recent results show that conversion effects with the same size and frequency dependence are observed in...

We demonstrate a laser ranging scheme that uses a high-frequency modulated beam to achieve subnanometer precision by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular, we show that the signal, which presents both...

We demonstrate a laser ranging scheme that uses a high-frequency modulated beam to achieve subnanometer precision by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular, we show that the signal, which presents both...

We present a laser ranging system, under development, that uses a high frequency modulated beam to achieve sub-nm resolution by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular we show that the signal, which presents...

Nous présentons deux télémètres basés sur un faisceau laser modulé en amplitude à haute fréquence (HF). L'information de distance est extraite de la phase du faisceau renvoyé par la cible. Dans la première mise en oeuvre proposée, l'erreur cyclique associée à une diaphonie optique entre la voie de référence et la voie de mesure est absente,...

We present a laser ranging system, under development, that uses a high frequency modulated beam to achieve sub-nm resolution by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular we show that the signal, which presents...

Absolute distance measurement with accuracy below the micron scale is important in astronomical optical interferometry. We present here an absolute laser rangefinder which relies on the detection of a two mode interference signal. We exploit the specific signature of the signal to extract both the interferometric and synthetic phase...

Les photodiodes rapides sont un composant crucial des dispositifs opto-microondes. Les défauts desphotodiodes (non-linéarités, diaphonies, couplages amplitude-phase, ?) interviennent à des degrésdivers dans les utilisations qui en sont faites pour transformer en un photocourant les informationstransportées par le faisceau. Le couplage AM-PM est...

High accuracy and low noise measurement of the phase of a microwave signal requires that spurious contributions are adequately dealt with. In this paper we investigate the power-to-phase coupling in two commercial high bandwidth P-I-N, near-IR photodetectors. We observe that a sudden change of the optical power induces a transient of the phase...

We investigate the power-to-phase coupling in two commercial high bandwidth P-i-N near-IR photodetectors. We observe that a sudden change of the optical power induces a transient of the phase of the 20 GHz signal, at different time scales. The temperature rise of the photodetector junction is likely to be involved in this dynamical behaviour....

Le vol en formation de satellites et l'alignement des collisionneurs de particules sont deux domainesoù la mesure de distance doit être faite avec une haute résolution et une haute exactitude.L'interférence hétérodyne utilisée pour les mesures de déplacement atteint des résolutions subnanométriques,mais il s'agit d'une mesure de phase: elle...

We present two different laser ranging systems under development, both based on the use of a high frequency modulated beam. The first range meter makes no use of interferometry: only the phase of the return beam is detected, in a way that rejects cyclic errors due to optical and electronic crosstalk. An Allan deviation slightly better than 10nm...

We investigate the power-to-phase coupling in two commercial high bandwidth P-i-N near-IR photodetectors. We observe that a sudden change of the optical power induces a transient of the phase of the 20 GHz signal, at different time scales. The temperature rise of the photodetector junction is likely to be involved in this dynamical behaviour....

Some measurement schemes have been proposed and realized for the absolute measurement of long distances with an accuracy better than 10 nm. Published measurement setups use one or even two laser frequency combs. But significant engineering will be required to space qualify such a system. Simple methods, less technology-demanding would be...

Some measurement schemes have been proposed and realized for the absolute measurement of long distances with an accuracy better than 10 nm. Published measurement setups use one or even two laser frequency combs. But significant engineering will be required to space qualify such a system. Simple methods, less technology-demanding would be...