Center for Applied Photonics

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Project Overview

Project

Title

Project leader(s)

01

Femto- and Attosecond Laser Sources Based on Ultrabroadband Fiber Optics

Brida, Seletskiy, Leitenstorfer

02

High-Power Mode-Locked Thin-Disc Lasers and Asynchronous Optical Sampling

Dekorsy
03

High-Field Terahertz Physics and Technology

Pashkin, Leitenstorfer, Dekorsy

04

High-Resolution Nanocrystal Analysis by Analytical Ultracentrifugation

Cölfen, Mecking
05

Manipulation of Anderson Localization of Light by Magnetic Fields

Maret, Aegerter
06

Photo-Conductance of Atomic-Size and Molecular Structures

Scheer, Boneberg
07 Integrated Optomechanical Devices Weig
08

Interaction of Quantum Structures and Quantum Light

Belzig, Pauly
09

Theory of Nanostructures as Interfaces between Spin Qubits and Photons

Burkard
10

Theory of Ultrafast Opto-Magnetic Writing Procedures

Nowak
11

Nonlinear Confocal Photomanipulation in Live Cells

Ferrando-May
12

3D Multi-Photon Functional Imaging of Neuronal Activity

Galizia
13

Infrared Laser Spectroscopy for Site-Specific Dynamics of Protein Folding

Hauser
14

Widefield Fluorescence Microscopy with Improved Longitudinal Resolution

Wöll
15

Coherent Raman Microscopy in Microfluidic Structures

Zumbusch

Project Details

Femto- and Attosecond Laser Sources Based on Ultrabroadband Fiber Optics

Project Leader: Brida, Seletskiy, Leitenstorfer
Title:

Femto- and Attosecond Laser Sources Based on Ultrabroadband Fiber Optics

Abstract:

The project proposes the development of low-noise and compact laser sources of phase-locked few-cycle pulses. It also aims at combining these fiber-based seed systems with high-power thin-disc technology for boosting the pulse energy to the multi-milliJoule level. We plan to demonstrate applications in ultraprecision and quantum metrology, as well as attosecond physics with solid-state nanostructures. Frequency conversion of high-energy transients to the multi-terahertz regime will enable generation of coherent pulses in the hard X-ray regime.

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High-Power Mode-Locked Thin-Disc Lasers and Asynchronous Optical Sampling

Project Leader: Dekorsy
Title:

High-Power Mode-Locked Thin-Disc Lasers and Asynchronous Optical Sampling

Abstract:

This project aims for the further development of femtosecond solid-state laser systems and their applications. More specifically, the first part of this project focuses on the improvement of high power mode-locked Yb:YAG thin disk lasers and of semiconductor saturable absorber mirrors (SESAM) required for these lasers. Besides exploring new SESAM designs, alternative mode-locking techniques will be investigated with this laser. The second part of the project deals with the development of compact dualfemtosecond laser sources for high-speed asynchronous optical sampling (ASOPS). In particular, ASOPS based on Yb-based oscillators operating at a wavelength of 1040 nm with a repetition rate around 500 MHz will be developed. A compact ASOPS system employing 10 GHz repetition-rate lasers will be pursued. The higher repetition rate results in a shorter data acquisition time which can be beneficial for high-speed THz time-domain spectroscopy and picoseconds ultrasonics.

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High-Field Terahertz Physics and Technology

Project Leader: Pashkin, Leitenstorfer,  Dekorsy
Title:

High-Field Terahertz Physics and Technology

Abstract:

The project proposes to extend the state-of-the-art high-field terahertz technology using novel high-power Yb- and Tm-based lasers and large-area terahertz emitters. Our goal is the study of non-perturbative excitation response in condensed matter driven by high-field terahertz pulses. We plan to achieve a detailed understanding of the light-matter interaction in semiconductors and strongly correlated electron systems as well as coherent dynamics in hydrogen-bonded liquids and high-temperature superconductors. 

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High-Resolution Nanocrystal Analysis by Analytical Ultracentrifugation

Project Leader: Cölfen, Mecking
Title:

High-Resolution Nanocrystal Analysis by Analytical Ultracentrifugation

Abstract:

The project proposes the development of multiwavelength detection and excitation analytical ultracentrifugation techniques for a characterization of inorganic nanocrystal emitters with a functional organic shell. Hybrid dual organic/inorganic semiconductor nanoparticles serve as probes for these method developments.

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Manipulation of Anderson Localization of Light by Magnetic Fields

Project Leader: Maret, Aegerter
Title:

Manipulation of Anderson Localization of Light by Magnetic Fields

Abstract:

In the most extreme case of multiple scattering of waves in disordered media the distance between scattering events may become smaller than the wavelength. This regime, commonly called strong or Anderson localization, has recently been demonstrated experimentally by us for visible light studying the spatio-temporal spreading of femtosecondlaser pulses in 3D powders of submicron sized titania particles. It arises from enhanced backscattering due to interference between “time reversed” multiple scattered waves setting up random localized modes. Goal of this project is to manipulate these modes by breaking the time reversal symmetry of wave propagation in strong magnetic fields due to magneto-optical Faraday rotation.

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Photo-Conductance of Atomic-Size and Molecular Structures

Project Leader: Scheer, Boneberg
Title:

Photo-Conductance of Atomic-Size and Molecular Structures

Abstract:

The project proposes the investigation of electromagnetic-field-induced conductance changes of atomic-size contacts, individual molecules contacted with atomically fine electrodes, molecular ensembles (1000 to 10000 molecules in parallel) contacted by the nanopore and the crossbar technique. The central subjects to be pursued over the next three years are aiming at (i) revealing the dominating mechanisms for fieldinduced conductance changes of metallic and molecular contacts by time-resolved and spatially resolved studies of photoconductance, (ii) the influence of optical antenna effects and surface plasmon polaritons (SPPs) by variation of the electrode geometry and simulation studies, (iii) light-induced thermoelectric effects in atomic and molecular systems, and (iv) the study of the photo-conductance of molecular systems.

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Integrated Optomechanical Devices

Project Leader: Weig
Title:

Integrated Optomechanical Devices

Abstract:

Nanomechanical systems with high mechanical quality factor are promising
candidates for sensing technologies as well as filtering and signal processing devices. Optical techniques provide exquisite control, including the possibility to exert lightinduced back-action to manipulate the mechanical state. This project proposes to develop an integrated approach combining nanomechanical resonators and optical cavities on a chip. Back-action effects including both light-induced cooling towards the quantum ground state, and pumping, leading to self-sustained oscillation, will be demonstrated, and strategies to implement hybrid nanosystems interfacing photonic, phononic, electronic and spin degrees of freedom will be explored.

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Interaction of Quantum Structures and Quantum Light

Project Leader: Belzig, Pauly
Title:

Interaction of Quantum Structures and Quantum Light

Abstract:

Quantum many-body systems interacting with electromagnetic fields are candidates for quantum interfaces in communication and nanoplasmonic applications. We will investigate the coupling of an electronic current in a nanoconstriction to a lightinduced plasmonicexcitation using both model-based approaches and numerical simulations aimed at realistic geometries. The combination of strong non-equilibrium and quantum many-body aspects requires the development of new methods to take into account the long-range Coulomb interaction and screening. The goal is to achieve a better understanding of the plasmon-enhanced coupling mechanism between light and electronic degrees of freedom. This concerns especially the geometrical details determining the coupling as well as aspects like quantum entanglement transfer.

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Theory of Nanostructures as Interfaces between Spin Qubits and Photons

Project Leader: Burkard
Title:

Theory of Nanostructures as Interfaces between Spin Qubits and Photons

Abstract:

The purpose of this research project is to build up the theoretical foundation for the relevant physical mechanisms at the interface between the quantum degrees of freedom of propagating photons and coherent single spins localized in solid-state nanostructures. A special focus of the project will be on carbon-based materials due to their potential for long-lived spin coherence. The mechanisms under study will be the optical injection of spin-polarized carriers into the nanostructures based on graphene, the coherent optical manipulation and mutual coupling of single spins in nanostructures, as well as the inter-conversion of quantum information from the electron spin state in the nanostructure and a quantum-mechanical degree of freedom (such as polarization) of a photon. Applications include carbon-based spintronics and spin-based quantum information processing and the implementation of quantum communication protocols over relatively long distances.

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Theory of Ultrafast Opto-Magnetic Writing Procedures

Project Leader: Nowak
Title:

Theory of Ultrafast Opto-Magnetic Writing Procedures

Abstract:

Innovative, pure optical routes for triggering magnetization switching in ferri- and antiferromagnets have recently been demonstrated. They rest on short laser pulses on femto- to picosecond time scales with either circularly or linearly polarized light. Several effects may be relevant for the magnetization reversal, as the inverse Faraday effect, the rapid heating of the material, or even the B-field component of the laser light. It is the aim of this project to investigate the physical mechanisms behind these opto-magnetic effects by means of computer simulation and to develop new optomagnetic writing schemes for switching on ultrashort time scales.

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Nonlinear Confocal Photomanipulation in Live Cells

Project Leader: Ferrando-May
Title:

Nonlinear Confocal Photomanipulation in Live Cells

Abstract:

Aim of this project is to establish nonlinear excitation with near-infrared (NIR) femtosecond pulses as a versatile, well-characterized and widely applicable tool to manipulate DNA in living cells. A state-of-the-art, high-throughput photomanipulation / confocal imaging system will be developed to investigate the influence of the pulse parameters wavelength, pulse duration and peak power on the spectrum of induced DNA lesions. The system will encompass three wavelengths (1050 nm, 775 nm and 525 nm). The lesions to be investigated include DNA single and double strand breaks, UV-photoproducts, oxidative base modifications and interstrand crosslinks. Structural alterations of chromatin in irradiated cells will be visualized by super-resolution imaging.

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3D Multi-Photon Functional Imaging of Neuronal Activity

Project Leader: Galizia
Title:

3D Multi-Photon Functional Imaging of Neuronal Activity

Abstract:

In this project, our goal is to develop and apply a novel multi-photon microscope to study olfactory coding in insects, specifically how fast neuronal processing segregates odor percepts in higher brain centers. This question specifically requires a sampling technique with high temporal and spatial resolution.
Multi-photon imaging of in-vivo brain activity provides key advantages in studying neuronal networks, such as parallel probing of many cells. However, classical multiphoton imaging suffers from drawbacks such as low temporal resolution or photodamage inflicted by the high excitation laser power, which hinder the methods applicability in many experimental situations.
To this end, we are collaboratively developing the necessary methodological advancements, which will allow us to overcome those caveats. Our approach to multiphoton imaging consists of the use of an Erbium:fiber laser, capable of generating short pulses which lead to efficient multi-photon excitation, while maintaining a low average energy to minimize photodamage in the sample. Combined with a high performance xyz-scanning unit, the sampling is restricted to areas of interest, thus maximizing sampling rate.

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Infrared Laser Spectroscopy for Site-Specific Dynamics of Protein Folding

Project Leader: Hauser
Title:

Infrared Laser Spectroscopy for Site-Specific Dynamics of Protein Folding

Abstract:

The project proposes the development of an infrared spectrometer using tunable quantum cascade lasers. It is combined with a pulsed Nd:YAG laser for rapid heating of the sample and to initiate fast temperature jumps. Main application is to study protein folding dynamics on the nanosecond-to-microsecond time-scale. The aim is to upgrade the current IR-Laser-spectrometer for 1) a broader IR frequency detection range, 2) simultaneous detection of several probe wavelengths, 3) additional probing in the visible frequency range. The analysis of side-chain and tertiary structure dynamics becomes feasible besides the backbone and secondary structure dynamics. Furthermore, applications shall be extended to functional studies of biomolecules in general.

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Widefield Fluorescence Microscopy with Improved Longitudinal Resolution

Project Leader: Wöll
Title:

Widefield Fluorescence Microscopy with Improved Longitudinal Resolution

Abstract:

The project proposes the investigation of interface effects on the glass transition temperature in thin polymer films. With an improved longitudinal resolution, i.e. resolution in z-direction parallel to the optical axis, using shaping of single molecule point spread functions, we will be able to position and track single molecule motion with an accuracy of few nanometers in all directions. This will allow us to determine the distance up to which interface effects influence the dynamics within polymer films and how this influence depends on the substrate, the polymer and film reparation.

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Coherent Raman Microscopy in Microfluidic Structures

Project Leader: Zumbusch
Title:

Coherent Raman Microscopy in Microfluidic Structures

Abstract:

Within this project, new approaches to label-free vibrational microscopy shall be employed to monitor the distribution of different molecular species in volumes on a micrometer scale. More specifically, we plan to further develop coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) microscopy in order to use it for the quantitative analysis of the chemical composition liquids in microfluidic devices. Similarly, we want to take the same approach to develop a flow cytometry experiment based on non-linear optical Raman microspectroscopy allowing us to distinguish cells transported through a microfluidic structure.

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