stillingsbetegnelse:
Two PhD scholarships on Photonic Crystals and Epitaxially Grown Nanostructures

jobbeskrivelse:

Two Ph.D. stipends including full salary are available at the Department of Photonics Engineering, Technical University of Denmark.

The research envisioned in the Ph.D. projects aim at exploring active photonic crystal structures with the purpose of realizing new types of nanolasers and ultra-fast all-optical switches and understanding the physics of these structures. This research theme is central to NATEC (“NAnophotonics for Terabit Communications”), which is a Centre of Excellence funded by Villum Fonden. The NATEC centre performs research on light-matter interaction in semiconductor quantum dots and photonic crystal structures and explores the use of such nanostructured materials for realizing photonic chips operating in the terabit per second regime.

The centre is a strongly focused effort involving nanofabrication, experimental characterisation based on nanoscopy and ultrafast laser spectroscopy, fundamental theory including topology optimization, and systems experiments and provides ample opportunities for cross-fertilization between these areas. The Centre has been running for five years, during which world-class experimental and theoretical results have been obtained (for recent results see, e.g., S. Ek et al., Nature Comm., 5:5039,DOI:10.1038/ncomms6039 (2014), and J. Mork et al., Phys. Rev. Lett., vol. 113, 163901 (2014)). Moreinformation about NATEC is available at the webpage: see http://www.natec.dtu.dk.

The first Ph.D. project is focused on characterizing and understanding the fundamental properties of photonic crystal Fano structures. A so-called Fano resonance involves the interaction between a continuum and a discrete resonance. We have recently shown (see, e.g., Yi Yu et al., Appl. Phys. Lett., vol. 105, 061117 (2014)) that such resonances occur in a photonic crystal waveguide coupled to a nanocavity, and that the resonance can be used to realize a fast all-optical switch as well as an optical diode. In the present project we wish to further build on these promising results and explore ideas for the use of Fano resonances to realize an ultrafast laser as well as other types of switches. The project is mainly experimental, including design and processing of devices using e-beam lithography and subsequent characterization of optical and dynamical properties. The project will also involve numerical simulations using existing tools as well as the development and analysis of simplified mathematical models for understanding the device physics.

The second Ph.D. project is targeting the underlying technologies for the next generation devices. Crucial to the devices in NATEC is nanoscale tailoring of the materials and characterization at the same scale. Accurate control of the position, shape and composition of quantum dots will allow the ultimate control of light-matter interaction when combined with the photonic crystal technology developed previously. The materials technology is based on MOVPE (re)growth, e-beam lithography and ICP etching (Kuznetsova et al, Journal of Crystal Growth, vol. 406, 111 (2014)).

The chemical structure is determined by Scanning Transmission Electron Microscopy (STEM) available in-house (Kadkhodazadeh et al., J. Crystal Growth, vol. 329, 57 (2011)), while atom probe tomography (APT) will be carried out with collaborators. The project will also involve modelling, design and optical characterization, and will take place in close collaboration with researchers focusing on device properties. The project is expected to lead to the first demonstration of an ultrafast photonic crystal Fano laser.

Qualifications Candidates should have obtained a master''s degree in physics or electrical engineering with very good results (high GPA) and have a strong interest and background in several of the following topics: photonics, lasers, semiconductor physics, quantum mechanics, and electromagnetic field theory. Candidates should have strong analytical ski

Arbejdsgiver Navn: Danmarks Tekniske Universitet

Arbejdsgiver telefonnummer: 45252525

Arbejdsgiver faxnummer: 45881799

Job kort beskrivelse:
Undervisning og forskning på universiteter og højere læreranstalter

land: Danmark

region: Hovedstaden

krævede uddannelse: Ikke angivet

Kilde til jobtilbud: AMS, Offentlige arbejdsformidlinger, Danmark