Blar i NTNU Open på forfatter "Skaar, Johannes"
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Magnetic permeability in Fresnel’s equation
Hågenvik, Hans Olaf; Skaar, Johannes (Journal article; Peer reviewed, 2019)Magnetic permeabilities derived for infinite, periodic media are used in the Fresnel equation to calculate the reflection from corresponding semi-infinite media. By comparison to finite-difference time-domain (FDTD) ... -
Metamaterial effective parameters
Dirdal, Christopher Andrew (Doctoral theses at NTNU;2017:181, Doctoral thesis, 2017)Metamaterials are a class of composite materials acting as effectively continuous media, which are capable of realizing entirely new phenomena such as negative refraction and transformation optics. They have thereby opened ... -
Modelling of multimode and layer structure by transfermatrices
Sveinsson, Helge Mjølhus (Master thesis, 2010)Modelling of multimode and layer structure by transfermatrices -
Modifications of the Kramers-Kronig Relations for the Magnetic Permeability
Bondevik, Tarjei (Master thesis, 2014)The Kramers-Kronig (KK) relations provide a mathematical relation between the real and imaginary part of a complex function that is analytic in the upper half plane and tends to zero as the argument tends to infinity. The ... -
Negative Refraction in Non-Magnetic Metamaterials
Dirdal, Christopher Andrew (Master thesis, 2012)The discoveries and subsequent developments within the field of metamaterials have opened up for novel light-matter interactions towards the engineering of light behavior. The astonishing phenomenon of negative refraction ... -
Photoluminescence Study of Enhanced Light Emission from HgCdTe Thin Films due to a Surface Pattern
Haugan, Espen Tunhøvd (Master thesis, 2015)HgCdTe thin film samples with a CdTe passivation layer have been grown by molecular beam epitaxy, and photolithography has been used to etch a triangular pattern of holes into the passivation layer. The enhancement in ... -
Quantum key distribution prototype
Tvedt, Ole Christian (Master thesis, 2010)This thesis covers the basics of cryptography, both classical and the newer quantum-basedapproches. Further, it details an implementation of a BB84-based quantum key distributionsystem currently under construction, focusing ... -
Security of QKD-systems with detector efficiency mismatch
Lydersen, Lars Vincent van De Wiel (Master thesis, 2008)The rules of quantum mechanics makes it possible to exchange a secret key at a distance. This is called quantum key distribution (QKD). In theory the key exchange can be made completely secure. Real QKD implementations ... -
Security of quantum key distribution source
Simonsen, Eivind Sjøtun (Master thesis, 2010)Cryptography has begun its journey into the field of quantum information theory. Classical cryptography has shown weaknesses, which may be exploited in the future, either by development in mathematics, or by quantum ... -
Security of quantum key distribution with bit and basis dependent detector flaws
Lydersen, Lars; Skaar, Johannes (Journal article; Peer reviewed, 2010)We consider the security of the Bennett-Brassard 1984 (BB84) protocol for Quantum Key Distribution (QKD), in the presence of bit and basis dependent detector flaws. We suggest a powerful attack that can be used in systems ... -
Simulations and realizations of active right-handed metamaterials with negative refractive index
Nistad, Bertil; Skaar, Johannes (Journal article; Peer reviewed, 2007)The theory of determining the sign of the refractive index in active materials is discussed. Animations of numerical simulations are presented, supporting the claim that negative refractive index may occur in right-handed ... -
Simulations of X-ray Propagation in Guiding Structures and Light Scattering From Coccoliths Using Finite Difference Methods
Kleiven, David (Master thesis, 2017)This thesis consists of two major parts. First, future applications of waveguides in the X- ray regime has been studied numerically. The second part is devoted to the study of light scattering from calcite shells from ... -
The Effect of Gain Saturation in a Gain Compensated Perfect Lens
Skaldebø, Aleksander Vatn (Master thesis, 2009)Perfect lenses operating in the near visible spectrum has only recently been introduced, and these kind of metamaterials seem to have a large potential. One problem encountered with these perfect lenses are exceedingly ... -
Total internal reflection and evanescent gain
Grepstad, Jon Olav; Skaar, Johannes (Journal article; Peer reviewed, 2011)Total internal reflection occurs for large angles of incidence, when light is incident from a high-refractive-index medium onto a low-index medium. We consider the situation where the low-index medium is active. By invoking ... -
Towards secure and efficient quantum key distribution
Marøy, Øystein (Doctoral theses at NTNU;2019:206, Doctoral thesis, 2019) -
Understanding complementarity-based security proofs of quantum key distribution with imperfect sources
Gulla, Jan (Master thesis, 2017)We present a study of modern security proofs of quantum key distribution based on complementarity. This is a quantum communication protocol allowing for provable, unconditional security, although there is still a gap between ...