Modeling the Bulk and Nanometric Dielectric Functions of Au and Ag

In this work, we model the dielectric functions of gold (Au) and silver (Ag) which are typically used in photonics and plasmonics. The modeling has been performed on Au and Ag in bulk and in nanometric states. The dielectric function is presented as a complex number with a real part and an imaginary part. First, we will model the experimental measurements of the dielectric constant as a function of the pulsation ω by appropriate mathematical functions in an explicit way. In the second part we will highlight the contributions to the dielectric constant value due to intraband and interband electronic transitions. In the last part of this work we model the dielectric constant of these metals in the nanometric state using several complex theoretical models such as the Drude Lorentz theory, the Drude two-point critical model, and the Drude three-point critical model. We shall comment on which model fits the experimental dielectric function best over a range of pulsation.

О токовой зависимости эффективности инжекции и относительном вкладе скорости эмиссии и внутренних оптических потерь в насыщение ватт-амперной характеристики мощных импульсных лазеров (λ=1.06 мкм)

The results of numerical simulation of the current dependence of the injection efficiency in the active area of the laser based on separate confinement heterostructures are presented. The feature of the transfer of charge carriers through isotype N-n heterotransitions on the interface boundary of waveguide and active areas is shown. Using the classic dependencies of the Drude-Lorentz theory, the cross-section of electrons and holes for the GaAs waveguide was evaluated. The resulting values of σe= 1.05∙10-18 cm2 and σp= 1.55∙10-19 cm2 and current dependencies of the injection efficiency allowed to determine the root-cause reason for the pulse power saturation of semiconductor lasers. It has been established that saturation of power-current characteristics is dominated by holes escape from the active region to the waveguide and internal optical losses are lower confinement factors.

Anti-Relativity in Action: The Scientific Activity of Herbert E. Ives between 1937 and 1953

Between 1937 and 1953 the industrial physicist Herbert E. Ives pursued an extended research program with the aim of challenging the acceptance of relativity theories, and became the most important American opponent of Einstein during that era. As part of his anti-relativistic efforts Ives also performed the famous Ives-Stilwell experiment. Usually interpreted as the first direct confirmation of the time dilation formula of special relativity theory, this experiment was regarded by Ives as proof of what he called the Larmor-Lorentz theory. Ives’s heterodox views about relativity were mainly ignored by the scientific community during his lifetime. After his death, however, his criticisms of what the majority of physicists took for granted helped spark philosophical discussions in the late 1950s concerning the conventional stipulation of distant simultaneity in special relativity theory. Ives’s anti-relativistic beliefs and actions allow for an analysis of the heterodox efforts of an accredited member of the scientific community and the subsequent process of his professional marginalization in a specific historical and scientific context. This paper has three aims: to uncover the epistemic roots of Ives’s opposition to relativity; to analyze Ives’s rhetorical strategies and the reasons why he failed to persuade his peers; and to reveal the divergence between the public network of allies Ives built in scientific publications and the hidden network of allies present in his correspondence. It will become clear that the hardening of Ives’s tone against relativity and Einstein can be understood in light of his progressive marginalization and loss of recognized socioprofessional identity due to his unorthodox ideas. Ives’s case is illuminating for the historical, philosophical, and sociological perspectives it provides on the complex mechanisms by which the margins interact with the mainstream of science, both in the production of certified knowledge and in the contextually contingent redefinition and reconfiguration of the boundaries of acceptable scientific discourse.