The research programs carried out in the participating groups are highlighted in the following.
DTU Physics
Nonlinear Optics is an important tool in the development of novel light sources targeting specific applications. The light sources are based on non-linear frequency mixing of efficient solid-state or semiconductor based laser systems.
Specifically generic approaches are sought for the development of coherent light sources in the UV visible and Mid-IR spectral range. The light sources are designed and tailored for specific applications, e.g. in terms of wavelength, tuneablilty, pulse duration, and pulse energy.
Applications are within bio-medicine: e.g. as excitation light source for fluorescence spectroscopy, Raman spectroscopy and within dermatology. Applications for Mid-IR systems are gas sensing: e.g. in monitoring combustion systems or environment control. Please see www.dtu.dk/centre/OPTIK/English.aspx
Quantum information science holds the promise of sending information over long distance with unconditional security and the promise of exponentially speeding up some computational tasks. Such revolutionary new protocols can be constructed by the aid of quantum optics. We are conducting experiments on the preparation of states of light with manifestly nonclassicality, on the processing a quantum in pure quantum protocols and on the development of new detection schemes capable of measuring quantum states with exquisite accuracy. For more information see www.quin.fysik.dtu.dk/English.aspx
DTU Fotonik
Nanophotonic semiconductor light sources are promising candidates for a scalable quantum information technology that provide an interface between light and matter. In the Quantum Photonics Group at DTU Fotonik, we investigate the interaction between photons and quantum dots in, e.g., photonic crystals or plasmonic nanowires. Our aim is to achieve coherent control of light-matter interaction at the single photon level. For more information, see: www.fotonik.dtu.dk/quantumphotonics
At DTU Fotonik an extensive effort is dedicated to diode lasers and their use for demanding scientific as well as industrial applications. Such applications includes frequency conversion in second order nonlinear materials (Sum or difference frequency generation), materials processing, generation of coherent light of predetermined wavelength and as exitation light sources for fluorescence spectroscopy. The key components are tapered semiconductor amplifiers combined with advanced resonator geometries leading to high output power, high temporal as well as spatial coherency.
 |
Example of nanophotonic device that will be used to extract single photons from a quantum dot with very high efficiency. A quantum dot (green dipole) is optically excited (large arrow) and decays into the surface plasmon mode of the nanowire (gray wire). The plasmon is coupled to a nearby waveguide (dark blue waveguide) whereby a single photon can be coupled out in a well-defined direction (small arrow) with high efficiency. |
The Niels Bohr Institute (NBI)
The research at NBI is divided into the ultra cold atoms group and the research center QUANTOP.
The ultra cold atoms group (J. W. Thomsen) performs experiments on ultra cold magnesium and sodium atoms. By a combination of lasers and magnetic fields the group cools and traps atom at extremely low temperatures (10-6-10-9 K). The structure of magnesium makes it highly suited for atomic clocks and the group is working on making an ultra precise atomic clock based on an optical transition. The group also develops new fiber lasers.
The QUANTOP center at NBI consists of the quantum optics laboratory (E. Polzik and J.-H. Müller) and the theoretical quantum optics group (A. S. Sørensen). The main focus of the center is in the field of quantum information processing, which aims at exploiting the laws of quantum mechanics to obtain powerful new methods of processing information. The quantum optics laboratory mainly works on developing methods for interfacing quantum states of light and atoms, which is important for quantum communication protocol. In addition the group also does experiments on Bose-Einstein condensation. The theoretical quantum optics group develops theories for how to engineer the quantum state of various systems. In particular the group investigates the implementation of quantum information processing in atomic ensembles and solid state systems and also carries out research on ultra cold atoms.