Liquid crystal tunable claddings for polymer integrated optical waveguides

• José M. Otón,
• Manuel Caño-García,
• Fernando Gordo,
• Eva Otón,
• Morten A. Geday and
• Xabier Quintana

Beilstein J. Nanotechnol. 2019, 10, 2163–2170, doi:10.3762/bjnano.10.209

• passive, turning them into tunable devices able to drive and modulate light signals. One possible way that has attracted increasing interest in the last five years is the use of photonic circuits based on silicon. Silicon photonics can be employed in the NIR range at wavelengths longer than 1100 nm. This

• integrating electronic and photonic components in the same circuit. The main drawback for silicon waveguides to become tunable devices is the big difference in refractive indices between the core (Si, n > 3.0) and the cladding (SiO2, n < 1.50). This difference confines the propagating wave inside the core

• are quite close to each other; the second may often lead to complex manufacturing processes and results less manageable for preparing tunable devices. Polymer waveguides (PWGs) are well suited for preparing devices having LC cladding. Indeed, the refractive index of PWGs is typically in the range of

Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials

• Daniela Dragoman

Beilstein J. Nanotechnol. 2018, 9, 1828–1833, doi:10.3762/bjnano.9.174

• discrete fractional Fourier transform, in particular the discrete Fourier transform, and thus can act as a coprocessor in integrated logic circuits. Keywords: atomically thin materials; Fourier transform; tunable devices; Introduction Despite continuous advances in nanotechnology, existing Boolean

Robust midgap states in band-inverted junctions under electric and magnetic fields

• Álvaro Díaz-Fernández,
• Natalia del Valle and
• Francisco Domínguez-Adame

Beilstein J. Nanotechnol. 2018, 9, 1405–1413, doi:10.3762/bjnano.9.133

• semiconductor bands can be tailored by the electric field. Tunable devices are thus likely to be realizable, exploiting the properties studied herein. Keywords: crystalline topological insulators; electric and magnetic fields; Landau levels; midgap states; Introduction In 1982, Thouless et al. [1] made a

Flexible photonic crystal membranes with nanoparticle high refractive index layers

• Torben Karrock,
• Moritz Paulsen and
• Martina Gerken

Beilstein J. Nanotechnol. 2017, 8, 203–209, doi:10.3762/bjnano.8.22

• resonance both with nanoparticle layer thickness and with strain. Due to the large possible deformations and color changes such photonic crystals membranes are highly promising for tunable devices as well as for visualization devices. Results and Discussion We observe resonances in the transmission spectrum