Nonparabolic effects in multiple quantum well structures and influence of external magnetic field on dipole matrix elements

We present a method of modeling of nonparabolic effects (NPE) in quantum nanostructures by using second order perturbation theory. We apply this model on multiple quantum well structures and consider the influence of external magnetic field on dipole matrix element which is usually considered constant. The dipole matrix element directly influences the optical gain, and our model can provide a better insight to how NPE and magnetic field influence the gain of quantum nanostructures

Modeling of the optical gain in ZnO-based quantum cascade lasers

ZnO has been proposed recently as a good base material for high-power terahertz quantum cascade lasers (QCLs) operating at room temperature. We have developed a theoretical model for calculation of the optical gain, based on solving the system of rate equations and taking into account relevant scattering mechanisms. This model has been implemented to perform numerical simulations using ZnO/ZnMgO material combination, starting from the conventional design with three well within the active region of the structure. The influence of the layer widths and composition on the output properties has been considered, together with the variation of the number of quantum wells per QCL period.XVIII Young Researchers' Conference Materials Sciences and Engineering : program and the book of abstracts; December 4-6, 2019; Belgrad

Grant agreement for project financed by EU funds – what improvements are necessary to support the absorption of EU funding in Croatia?

Grant Agreement in EU financed projects is an important segment of project implementation therefore its role is the key to better absorption of EU funding. In the upcoming financial perspective (2021 – 2027), it is necessary to improve project preparation process, increase the equality of parties as well as simplify the procedure of amending the Grant Agreement in order to increase project implementation effectiveness and achievement of project objectives thus contributing towards better absorption of EU funds. The objective of this paper is to identify and analyze key areas of the Grant Agreement that could be amended for the upcoming financial perspective and provide recommendations for improvement

Dwell time and group delay in negative index metamaterials

U radu su analizirani vremenski parametri koji opisuju prostiranje elektromagnetnih talasa kroz barijeru načinjenu od disperzivnog i apsorbujućeg materijala. Cilj je bilo izvođenje upštene relacija koja opisuje vezu između vremena zadržavanja i grupnog kašnjenja koja bi bila validna za sve tipove materijale, uključujući i metamaterijale sa negativnim indeksom prelamanja. Numerički proračun sproveden je za različite kombinacije materijala u barijeri i okolnom talasovodu, a prikazani rezultati su u potpunoj saglasnosti sa teorijskim predviđanjima.In this paper we have analyzed time-related properties of propagation of electromagnetic waves through a barrier made of dispersive and absorptive material. The goal was to derive a more general expression that describes the correlation between the dwell time and the group delay, valid for all types of materials, including negative index metamaterials. Numerical calculations were performed for various combinations of barrier materials and surrounding waveguide materials, and the presented results are in complete accordance with theoretical predictions.52. konferencija ETRAN-a : Jun 8-12, Palić, 2008.MO3.2-1-